Wycombe took a huge step towards reaching the League One play-off final as they beat Fleetwood 4-1 in a madcap encounter at Highbury on Friday night.
Nnamdi Ofoborh's drive set Gareth Ainsworth's men on their way (2) but Ched Evans levelled from the penalty spot (4), before Alex Cairns took Joe Jacobson's corner over the line to restore the visitors' lead (6).
Fleetwood were reduced to 10 men when Lewie Coyle was sent off after 33 minutes and they fell further behind thanks to goals from David Wheeler (45+3) and Alex Samuel (57).
The hosts' miserable evening was compounded when substitute Paddy Madden was dismissed after just 18 minutes on the pitch, following furious protests when he was denied a penalty late on.
How the Chairboys cruised in Lancashire
After a tepid affair in the earlier play-off semi-final draw between Portsmouth and Oxford, there was an appetite for some traditional drama and it came almost immediately when Ofoborh thundered the opener after Matt Bloomfield's square ball to the edge of the area.
Just seconds later, Evans tucked home a contentiously awarded penalty after a foul on Lewis Gibson but parity didn't last long, with a trademark Jacobson corner catching out Cairns, who was credited with taking the ball over his own goal-line.
The game failed to settle and continued at a fast and furious pace. Just after the half-hour mark Coyle was dismissed for a reckless lunge on Jacobson, but Cairns redeemed himself by keeping out the subsequent penalty with a strong arm and then recovering well to deny Wheeler.
Wheeler got in on the act with a first-time volley in first half stoppage-time and shortly after the restart, Samuel put the result beyond doubt when he took advantage of a missed punch from Cairns to acrobatically fire home a fourth.
With six minutes to play, Madden was pulled back by Darius Charles inside the area, but when referee Tony Harrington booked him for diving instead, he appeared to direct his verbal protests towards the officials, earning a second booking in quick succession to round off a quite dramatic evening.
Man of the match - Alex Samuel
The 24-year-old certainly won't have played as much football as he'd have liked this season, but he caught the eye at Highbury, with co-commentator Lee Hendrie noting that he "had plenty of energy and caused so many problems" for Fleetwood. A similar display in the second leg will stand him in great stead for starting berth should the Chairboys get to Wembley.
What the managers said...
Fleetwood's Joey Barton: "We just had an off night. It was a big game for the lads and Wycombe, to be fair to them, got off to a flyer. We managed to pull away from that, get a goal and get ourselves back in it but you just have to say it was a disappointing night.
"We've got a group of lads in there who've given me everything since I walked into the football club. People will, rightly, be disappointed with elements of the game, but I'd rather it be 4-1 tonight than 4-1 on Monday because that would be the final nail in the coffin."
Wycombe's Gareth Ainsworth: "It's half time and we know that, so we're not going to get carried away but that group is so together that they can achieve. We get written off all the time, but this lot have got more heart than you can ever believe.
"I think they've shown discipline and humility tonight but it's half time and we've got plenty more to come on Monday. I'm not expecting anything but a really, really tough game."
The second leg at Adams Park will be live on Sky Sports Football on Monday, July 6 from 7.15pm. Kick-off is at 7.30pm.