Millwall came from behind to defeat Bradford City and take control of their League One play-off semi-final.

Tony McMahon had given the Bantams an early lead from the penalty spot after Joe Martin handled in the box.

But Lee Gregory's acrobatic strike, Steve Morison's header and Martin's superb free-kick put the Lions into a 3-1 lead at half-time of the first leg.

Filipe Morais missed Bradford's best chance for a second goal when he skewed wide despite being free in the box.

The result means that, going into Friday's second leg at The Den, Neil Harris' side have a real chance of reaching Wembley as they seek to regain their place in the Championship at the first time of asking.

• Millwall's win at Bradford as it happened

Millwall had finished the regular season one place ahead of the Bantams, but fell behind when Martin's outstretched hand prevented Morais a free header at goal and McMahon took full advantage from the spot.

But the lead lasted just two minutes as Gregory - who recently returned from stomach surgery - equalised with a superb shot on the turn after Morison's knockdown.

Bradford's defence struggled to deal with the combination of Gregory and Morison throughout, and the latter powered home a near-post header from a corner to give the visitors the lead.

Martin's curled free-kick into the corner of the net from about 30 yards out on the stroke of half-time to give Millwall something to defend.

Bradford looked the more likely to get the next goal, but could not find a way past goalkeeper Jordan Archer, with Nathan Clarke seeing a header well kept out.

Lee Evans also fired just wide twice, while Jamie Proctor felt he should have been awarded a penalty for a trip, but the referee waved play on as Millwall held on to take a lead back to their home ground, where they have won their last six games.

Bradford manager Phil Parkinson: "I thought we started the game well, got the goal, and then conceded two soft goals from set plays, which is unlike us.

"In the second half I thought we responded really well. It wasn't easy in that second half for the lads to go out and play as well as they did. But we couldn't get that goal back.

"I take a lot of heart from the way we played in the second half and I firmly believe that this tie is not over."

Millwall manager Neil Harris: "I'm obviously not going to hide the fact that we're really pleased with the day's work.

"There will be no complacency from my group, that's for sure. I think the first goal will be key.

"We know it will be difficult because Bradford will get the ball forward and try to put us under pressure, especially early on. We will rely on a really strong atmosphere at The Den."