Chelsea secured their first victory in Guus Hiddink's second spell as boss to move six points clear of relegation with a deserved win at Crystal Palace.
Oscar put the Blues ahead against the run of play, tapping home after being put through by Diego Costa.
Once they scored Chelsea dominated, deservedly doubling their advantage with a spectacular Willian strike.
Costa sealed the win with a tap-in for a goal his performance deserved after Palace failed to clear Willian's shot.
Interim boss Hiddink, who guided Chelsea to third in the Premier League, a Champions League semi-final and the FA Cup in his first spell at the club, remains unbeaten since taking over from Jose Mourinho last month.
The Blues' four-match run without defeat is their longest this season and moves last year's champions to 14th in the league, still 13 points adrift of a Champions League spot.
Chelsea's away form in the first half of the season has been dire, with just six points collected on their travels. Only bottom two clubs Aston Villa and Sunderland have fared worse.
In beating seventh-placed Palace for their first away win since August, the Blues made a convincing case that the second half of the season might be more fruitful.
Hiddink said he needed leaders to pull the club out of relegation trouble and in Costa the Dutchman had a player in that mould, driving his team forward at Selhurst Park and playing a part in all three goals.
Like the rest of the Blues squad during this season's dreadful title defence, the Spaniard - who had missed the goalless draw at Manchester United because of suspension - has been below par, but he gave one of his best displays of the campaign.
John Mikel Obi also shone, providing much-needed ballast to the Chelsea midfield.
The one disappointment for Hiddink was the injury to Eden Hazard, which ended the Belgian's match after just 15 minutes.
Before the match Hiddink had said last year's player of the season was "back in shape" after suffering a hip injury against Leicester and sustaining a knock in Monday's draw at Manchester United.
Ultimately, Chelsea did not need Hazard against Palace with the impressive forward trio of Costa, Willian and Oscar creating plenty in his absence.
It was Palace's first defeat in seven matches and they clearly missed key players, although Eagles boss Alan Pardew admitted that even with the likes of suspended Yohan Cabaye in the team his men would have struggled against Chelsea in such form.
The hosts, though, are a far less formidable side without the creativity of top scorer Cabaye in midfield, the pace of Yannick Bolasie on the flanks and Connor Wickham up front.
Palace are now without a win or a goal in their past three games, with Bolasie and Wickham not having played since the goalless Boxing Day draw against Bournemouth.
However, Pardew's side had their chances with Wilfried Zaha - making his 200th appearance for the club - shooting wide with the score goalless and scuffing another opportunity just before Willian scored.
Chelsea interim boss Guus Hiddink: "Do not go over the top, it is the first win after a worrying period with two draws so the team desperately needed the win and it was convincing.
"Everyone knows we have a lot of quality in our team, but sometimes champions have a tendency to be complacent and it can be difficult to get back and then wonder why we were champions.
"There is a long way to go, mathematically the possibility of Champions League is still there. The league is so strong but as long as we play like we did today I will be happy."
Crystal Palace manager Alan Pardew: "We were not at our strongest, we were missing key players and could not play our natural game.
"We will be looking at the market in case something comes through. It is important we kick into gear in the second half of the season. Things did not go our way and we have to respond and I have every confidence in this group that we will be in and around the top 10."
Full Time Match ends, Crystal Palace 0, Chelsea 3.
90:00 +3:15 Full timeFull Time Second Half ends, Crystal Palace 0, Chelsea 3.
90:00 +2:38John Obi Mikel (Chelsea) wins a free kick in the defensive half.
90:00 +2:38Foul by Marouane Chamakh (Crystal Palace).
90:00 +0:41Attempt saved. Jason Puncheon (Crystal Palace) left footed shot from outside the box is saved in the top centre of the goal. Assisted by Marouane Chamakh.
87:42Hand ball by Pedro (Chelsea).
87:08 SubstitutionSubstitution Substitution, Chelsea. Nemanja Matic replaces Oscar.
86:27Attempt missed. Diego Costa (Chelsea) left footed shot from the centre of the box is too high. Assisted by Willian.
86:00Corner, Chelsea. Conceded by Scott Dann.
84:44Attempt blocked. Oscar (Chelsea) left footed shot from the centre of the box is blocked. Assisted by Pedro.
83:29Foul by John Terry (Chelsea).
83:29Marouane Chamakh (Crystal Palace) wins a free kick in the attacking half.
82:27Foul by Cesc Fàbregas (Chelsea).
82:27Jason Puncheon (Crystal Palace) wins a free kick in the defensive half.
81:32Corner, Chelsea. Conceded by Damien Delaney.
79:39 SubstitutionSubstitution Substitution, Crystal Palace. Jonathan Williams replaces Lee Chung-yong.
79:15 BookingBooking Scott Dann (Crystal Palace) is shown the yellow card for a bad foul.
79:05Diego Costa (Chelsea) wins a free kick on the left wing.
79:05Foul by Scott Dann (Crystal Palace).
77:57Corner, Crystal Palace. Conceded by John Terry.
Oscar (Chelsea) wins a free kick in the attacking half.
75:18Foul by Jason Puncheon (Crystal Palace).
73:10Foul by César Azpilicueta (Chelsea).
73:10Wilfried Zaha (Crystal Palace) wins a free kick on the right wing.
69:47Attempt blocked. Pedro (Chelsea) left footed shot from the left side of the box is blocked. Assisted by Oscar with a headed pass.
67:04Foul by John Obi Mikel (Chelsea).
67:04Lee Chung-yong (Crystal Palace) wins a free kick in the attacking half.
66:25 SubstitutionSubstitution Substitution, Crystal Palace. Joe Ledley replaces Mile Jedinak.
66:14 SubstitutionSubstitution Substitution, Crystal Palace. Marouane Chamakh replaces Fraizer Campbell.
65:40 Goal scoredGoal! Goal! Crystal Palace 0, Chelsea 3. Diego Costa (Chelsea) left footed shot from the left side of the six yard box to the top left corner.
63:52Branislav Ivanovic (Chelsea) wins a free kick in the defensive half.
63:52Foul by Wilfried Zaha (Crystal Palace).
62:03Attempt blocked. Jason Puncheon (Crystal Palace) left footed shot from outside the box is blocked. Assisted by Lee Chung-yong.
59:49 Goal scoredGoal! Goal! Crystal Palace 0, Chelsea 2. Willian (Chelsea) right footed shot from outside the box to the top right corner. Assisted by Oscar.
58:48Attempt saved. Wilfried Zaha (Crystal Palace) left footed shot from the centre of the box is saved in the centre of the goal. Assisted by Fraizer Campbell.
56:46Diego Costa (Chelsea) wins a free kick on the left wing.
56:46Foul by Scott Dann (Crystal Palace).
56:09 BookingBooking Mile Jedinak (Crystal Palace) is shown the yellow card.
56:04Oscar (Chelsea) wins a free kick on the right wing.
56:04Foul by Mile Jedinak (Crystal Palace).
54:27Oscar (Chelsea) wins a free kick in the defensive half.
54:27Foul by Damien Delaney (Crystal Palace).
53:51Foul by Oscar (Chelsea).
53:51Jason Puncheon (Crystal Palace) wins a free kick in the attacking half.
52:27Attempt missed. Kurt Zouma (Chelsea) header from very close range is close, but misses to the left. Assisted by Willian with a cross following a set piece situation.
51:37Willian (Chelsea) wins a free kick on the right wing.
51:37Foul by Mile Jedinak (Crystal Palace).
50:55Corner, Chelsea. Conceded by James McArthur.
50:25Corner, Chelsea. Conceded by James McArthur.
45:00Second Half begins Crystal Palace 0, Chelsea 1.
45:00 +2:27 Half timeHalf Time First Half ends, Crystal Palace 0, Chelsea 1.
45:00 +1:33Attempt blocked. Jason Puncheon (Crystal Palace) left footed shot from outside the box is blocked.
45:00 +1:03Foul by Pedro (Chelsea).
45:00 +1:03Joel Ward (Crystal Palace) wins a free kick in the defensive half.
44:24Foul by Willian (Chelsea).
44:24Pape Souaré (Crystal Palace) wins a free kick on the left wing.
39:05Foul by Branislav Ivanovic (Chelsea).
39:05Wilfried Zaha (Crystal Palace) wins a free kick in the defensive half.
35:27Corner, Chelsea. Conceded by Scott Dann.
35:24Attempt saved. César Azpilicueta (Chelsea) left footed shot from the left side of the box is saved in the centre of the goal. Assisted by Oscar.
34:05Corner, Chelsea. Conceded by Joel Ward.
30:38Branislav Ivanovic (Chelsea) wins a free kick in the defensive half.
30:38Foul by Pape Souaré (Crystal Palace).
28:04 Goal scoredGoal! Goal! Crystal Palace 0, Chelsea 1. Oscar (Chelsea) right footed shot from the centre of the box to the centre of the goal. Assisted by Diego Costa.
27:27Cesc Fàbregas (Chelsea) wins a free kick in the defensive half.
27:27Foul by Lee Chung-yong (Crystal Palace).
26:10Foul by César Azpilicueta (Chelsea).
26:10Lee Chung-yong (Crystal Palace) wins a free kick in the defensive half.
24:49Attempt missed. Fraizer Campbell (Crystal Palace) right footed shot from the right side of the six yard box is high and wide to the right. Assisted by Jason Puncheon with a cross.
23:56Corner, Crystal Palace. Conceded by Kurt Zouma.
23:48Foul by Kurt Zouma (Chelsea).
23:48Wilfried Zaha (Crystal Palace) wins a free kick in the attacking half.
23:25Attempt saved. Damien Delaney (Crystal Palace) header from the centre of the box is saved in the top centre of the goal. Assisted by Jason Puncheon with a cross.
22:43Foul by Willian (Chelsea).
22:43Wilfried Zaha (Crystal Palace) wins a free kick on the left wing.
20:08Foul by John Obi Mikel (Chelsea).
20:08James McArthur (Crystal Palace) wins a free kick in the defensive half.
19:19Delay over. They are ready to continue.
18:31Delay in match Joel Ward (Crystal Palace) because of an injury.
17:59Attempt blocked. Pedro (Chelsea) right footed shot from outside the box is blocked. Assisted by Oscar.
16:21Attempt saved. Damien Delaney (Crystal Palace) header from the centre of the box is saved in the top left corner. Assisted by Jason Puncheon with a cross.
15:56Corner, Crystal Palace. Conceded by John Obi Mikel.
15:34 SubstitutionSubstitution Substitution, Chelsea. Pedro replaces Eden Hazard because of an injury.
14:02Foul by John Obi Mikel (Chelsea).
14:02Joel Ward (Crystal Palace) wins a free kick on the right wing.
12:09 BookingBooking Damien Delaney (Crystal Palace) is shown the yellow card for a bad foul.
12:05Diego Costa (Chelsea) wins a free kick in the attacking half.
12:05Foul by Damien Delaney (Crystal Palace).
10:13Foul by Cesc Fàbregas (Chelsea).
10:13Damien Delaney (Crystal Palace) wins a free kick in the defensive half.
8:37Corner, Chelsea. Conceded by Mile Jedinak.
8:35Attempt blocked. Eden Hazard (Chelsea) right footed shot from outside the box is blocked. Assisted by Diego Costa.
6:49Attempt missed. Wilfried Zaha (Crystal Palace) right footed shot from outside the box is close, but misses to the left. Assisted by James McArthur.
5:34Corner, Crystal Palace. Conceded by Kurt Zouma.
4:29Delay over. They are ready to continue.
3:43Delay in match César Azpilicueta (Chelsea) because of an injury.
1:43Oscar (Chelsea) wins a free kick in the attacking half.
1:43Foul by Mile Jedinak (Crystal Palace).
0:25Corner, Crystal Palace. Conceded by Kurt Zouma.
0:00First Half begins.
0:00Lineups are announced and players are warming up.
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