Ipswich cemented their position in the play-off places as Brighton failed to win for a fifth successive match.
Daryl Murphy gave Ipswich the lead as the Irishman pounced on Lewis Dunk's mistake and fired in off the post for his first goal since 28 November.
Brighton's Jamie Murphy had an effort disallowed just before the goal, while Town's Kevin Bru twice hit the woodwork in the first half.
Substitute Bobby Zamora hit the bar for Albion in the second period.
The win took Ipswich four points clear of seventh-placed Sheffield Wednesday, while long-time Championship leaders Brighton are fourth, five points behind leaders Middlesbrough.
Ipswich showed their attacking intent early on as Bru hit the bar with a long-range effort after 15 minutes, while Brighton's Murphy was denied by an offside flag after Dean Gerken had saved Dale Stephens' close-range effort.
Ipswich went ahead soon afterwards as Dunk was caught in possession, allowing Daryl Murphy to score from a tight angle, and Town could have doubled their lead when Bru hit the post before half-time.
Brighton brought on Zamora and fellow striker James Wilson in a bid to find the net, but Chris Hughton's side have now gone three league games without a goal.
Zamora came closest to equalising but his effort from Bruno's cross cannoned off the crossbar.
Full Time Match ends, Brighton and Hove Albion 0, Ipswich Town 1.
90:00 +4:27 Full timeFull Time Second Half ends, Brighton and Hove Albion 0, Ipswich Town 1.
90:00 +3:29Corner, Ipswich Town. Conceded by Bruno.
90:00 +3:07Corner, Ipswich Town. Conceded by Connor Goldson.
90:00 +2:10Hand ball by Luke Hyam (Ipswich Town).
89:41Hand ball by Lewis Dunk (Brighton and Hove Albion).
88:57Attempt blocked. Dale Stephens (Brighton and Hove Albion) left footed shot from the right side of the box is blocked. Assisted by Bobby Zamora.
86:09Attempt missed. Andrew Crofts (Brighton and Hove Albion) header from the centre of the box misses to the right. Assisted by Rajiv van La Parra with a cross following a corner.
85:55 SubstitutionSubstitution Substitution, Ipswich Town. Luke Varney replaces Daryl Murphy.
84:57Corner, Brighton and Hove Albion. Conceded by Jonas Knudsen.
82:14Attempt missed. Elvis Manu (Brighton and Hove Albion) right footed shot from the centre of the box misses to the right. Assisted by Bruno following a fast break.
81:02 BookingBooking Íñigo Calderón (Brighton and Hove Albion) is shown the yellow card for a bad foul.
80:58Foul by Íñigo Calderón (Brighton and Hove Albion).
80:58Luke Hyam (Ipswich Town) wins a free kick in the defensive half.
78:47Corner, Ipswich Town. Conceded by Íñigo Calderón.
76:23 SubstitutionSubstitution Substitution, Brighton and Hove Albion. Elvis Manu replaces Jamie Murphy.
76:06 SubstitutionSubstitution Substitution, Ipswich Town. Brett Pitman replaces Ryan Fraser.
74:35Bobby Zamora (Brighton and Hove Albion) hits the bar with a right footed shot from the centre of the box. Assisted by Bruno with a cross.
73:01Corner, Brighton and Hove Albion. Conceded by Christophe Berra.
72:44Offside, Ipswich Town. Cole Skuse tries a through ball, but Daryl Murphy is caught offside.
Attempt blocked. Luke Chambers (Ipswich Town) right footed shot from outside the box is blocked.
72:00Attempt saved. Ryan Fraser (Ipswich Town) right footed shot from outside the box is saved in the top centre of the goal. Assisted by Daryl Murphy.
71:16Attempt missed. Rajiv van La Parra (Brighton and Hove Albion) left footed shot from the right side of the box is close, but misses to the right following a set piece situation.
70:13Bobby Zamora (Brighton and Hove Albion) wins a free kick on the right wing.
70:13Foul by Jonas Knudsen (Ipswich Town).
68:23Andrew Crofts (Brighton and Hove Albion) wins a free kick in the defensive half.
68:23Foul by Luke Hyam (Ipswich Town).
66:21Offside, Brighton and Hove Albion. Bobby Zamora tries a through ball, but Jamie Murphy is caught offside.
64:20 SubstitutionSubstitution Substitution, Brighton and Hove Albion. James Wilson replaces Beram Kayal.
64:12 SubstitutionSubstitution Substitution, Brighton and Hove Albion. Bobby Zamora replaces Tomer Hemed.
63:43Corner, Brighton and Hove Albion. Conceded by Ryan Fraser.
63:07Corner, Brighton and Hove Albion. Conceded by Ryan Fraser.
60:12Attempt missed. Tomer Hemed (Brighton and Hove Albion) header from the centre of the box is too high. Assisted by Jamie Murphy with a cross following a corner.
59:46Corner, Brighton and Hove Albion. Conceded by Jonathan Douglas.
59:17Andrew Crofts (Brighton and Hove Albion) wins a free kick in the defensive half.
59:17Foul by Luke Hyam (Ipswich Town).
58:40Attempt missed. Rajiv van La Parra (Brighton and Hove Albion) right footed shot from outside the box misses to the right. Assisted by Beram Kayal following a set piece situation.
57:53Beram Kayal (Brighton and Hove Albion) wins a free kick in the attacking half.
57:53Foul by Cole Skuse (Ipswich Town).
54:46Attempt saved. Jonathan Douglas (Ipswich Town) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Ryan Fraser.
54:45Attempt missed. Ryan Fraser (Ipswich Town) left footed shot from the left side of the box misses to the right. Assisted by Freddie Sears with a cross.
54:14Foul by Rajiv van La Parra (Brighton and Hove Albion).
54:14Cole Skuse (Ipswich Town) wins a free kick in the defensive half.
53:28Corner, Ipswich Town. Conceded by Íñigo Calderón.
52:15 SubstitutionSubstitution Substitution, Ipswich Town. Luke Hyam replaces Kevin Bru.
49:44Attempt missed. Andrew Crofts (Brighton and Hove Albion) right footed shot from outside the box misses to the right.
46:01Attempt saved. Dale Stephens (Brighton and Hove Albion) left footed shot from outside the box is saved in the centre of the goal. Assisted by Tomer Hemed with a headed pass.
45:00Second Half begins Brighton and Hove Albion 0, Ipswich Town 1.
45:00 +1:09 Half timeHalf Time First Half ends, Brighton and Hove Albion 0, Ipswich Town 1.
38:09Attempt saved. Ryan Fraser (Ipswich Town) right footed shot from outside the box is saved in the centre of the goal. Assisted by Freddie Sears.
37:05Corner, Ipswich Town. Conceded by Connor Goldson.
37:01Kevin Bru (Ipswich Town) hits the left post with a right footed shot from the centre of the box. Assisted by Ryan Fraser.
35:46Corner, Ipswich Town. Conceded by Íñigo Calderón.
33:53 BookingBooking Kevin Bru (Ipswich Town) is shown the yellow card.
33:22Attempt missed. Jonas Knudsen (Ipswich Town) left footed shot from outside the box misses to the right. Assisted by Freddie Sears.
31:42 Goal scoredGoal! Goal! Brighton and Hove Albion 0, Ipswich Town 1. Daryl Murphy (Ipswich Town) right footed shot from the right side of the box to the centre of the goal.
30:05Attempt blocked. Rajiv van La Parra (Brighton and Hove Albion) right footed shot from outside the box is blocked.
28:27Offside, Brighton and Hove Albion. Dale Stephens tries a through ball, but Jamie Murphy is caught offside.
28:26Dale Stephens (Brighton and Hove Albion) hits the bar with a right footed shot from the centre of the box. Assisted by Tomer Hemed with a cross.
27:15Dale Stephens (Brighton and Hove Albion) wins a free kick in the attacking half.
27:15Foul by Cole Skuse (Ipswich Town).
25:44Attempt blocked. Jamie Murphy (Brighton and Hove Albion) right footed shot from outside the box is blocked. Assisted by Tomer Hemed.
25:01Offside, Ipswich Town. Freddie Sears tries a through ball, but Daryl Murphy is caught offside.
22:49Attempt saved. Rajiv van La Parra (Brighton and Hove Albion) right footed shot from the left side of the box is saved in the bottom right corner. Assisted by Andrew Crofts.
21:27Corner, Ipswich Town. Conceded by Íñigo Calderón.
20:22Foul by Andrew Crofts (Brighton and Hove Albion).
20:22Kevin Bru (Ipswich Town) wins a free kick in the defensive half.
16:48Offside, Brighton and Hove Albion. Lewis Dunk tries a through ball, but Bruno is caught offside.
15:34Foul by Cole Skuse (Ipswich Town).
15:34Beram Kayal (Brighton and Hove Albion) wins a free kick in the defensive half.
15:01Corner, Ipswich Town. Conceded by David Stockdale.
14:57Attempt blocked. Cole Skuse (Ipswich Town) right footed shot from outside the box is blocked.
14:38Attempt blocked. Ryan Fraser (Ipswich Town) right footed shot from the left side of the box is blocked. Assisted by Kevin Bru.
14:25Kevin Bru (Ipswich Town) hits the bar with a right footed shot from outside the box.
11:02Attempt missed. Beram Kayal (Brighton and Hove Albion) right footed shot from outside the box misses to the right. Assisted by Bruno.
7:49Foul by Kevin Bru (Ipswich Town).
7:49Jamie Murphy (Brighton and Hove Albion) wins a free kick on the left wing.
4:06Ryan Fraser (Ipswich Town) wins a free kick in the defensive half.
4:06Foul by Bruno (Brighton and Hove Albion).
3:12Offside, Brighton and Hove Albion. Bruno tries a through ball, but Tomer Hemed is caught offside.
0:43Offside, Brighton and Hove Albion. Jamie Murphy tries a through ball, but Tomer Hemed is caught offside.
0:00First Half begins.
0:00Lineups are announced and players are warming up.
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