Blair Spittal was the Hearts hero as his 86th-minute winner earned the Scottish Premiership leaders a 2-1 comeback win over nine-man Hibernian in the Edinburgh derby - on a day of late drama in the title race.
Spittal came off the bench to curl home from inside the box - after Hibernian's ill-discipline cost them dearly in seeing goalkeeper Raphael Sallinger and then defender Felix Passlack sent off in both halves.
The victory moves Hearts three points clear of second-placed Celtic and four clear of Rangers in third.
It was an electric derby from the get-go. As news of spilled through to a buoyant Hearts side, many billed this as the Jam Tarts' big opportunity to take a huge step towards the Scottish Premiership title.
But Hibs - who won the last derby at Easter Road in December and whose fans are desperate to stop Hearts whatever it takes - initially had other ideas with a spirited display.
First, derby day specialist Martin Boyle crashed in a close-range finish for Hibs after seven minutes, latching onto Jamie McGrath's dangerous free-kick.
Easter Road was bouncing, but Hibs' game plan unravelled seven minutes later. Goalkeeper Sallinger was put under pressure and picked up a long ball forward, with VAR spotting he had taken it out the area. Referee Don Robertson brandished a red card after visiting the monitor.
Holding onto a lead against the league leaders with 10 men is hard enough - Hibs showed that as Claudio Braga missed two big first-half chances to level. But with nine men? Virtually impossible.
That became the case when Passlack was given his marching orders for a high challenge on Beni Baningime. Referee Robertson gave him a second yellow, when it could easily have been another straight red.
Hearts put on the pressure as Marc Leonard crashed against the bar, as wave after wave of attack came with little pressure on reserve goalkeeper Jordan Smith.
But Hearts got the goal their possession deserved when Lawrence Shankland's near-post flick was diverted into his own net by Warren O'Hora. An unfortunate moment amid some defiant defending.
Despite having a two-man advantage, Hearts were not able to put too much more pressure on the Hibs goal after levelling.
But after good work from Sabah Kerjota on the right, Spittal found the bottom corner with minutes remaining to snatch all three points.
The win moves Hearts three points ahead of Celtic - and four ahead of Rangers with four games to go with Hearts' next fixture a mouthwatering clash with Rangers next weekend, live on Your Site on May 4.
"We want to do it," said captain Shankland to Your Site at full-time. "We're close enough. We've worked so hard to get to this point and it's important we go and try to finish it off."
Hibs, who remain fifth, will hope the Glasgow teams stop Hearts from claiming the title, when they could not.
Hearts head coach Derek McInnes on Your Site:
"We stayed calm, stayed disciplined. When we need someone, our captain does it again. We then need the winner and Blair Spittal scores goals like that every day. Nice sidefoot finish and it could be such an important goal.
"To win any derby you have to do a lot right. The game was a bit unusual, but I thought we just about deserved a win.
"Anybody who says they're not interested in how the others are doing is telling lies. I would always watch the games. For us, the way the kick-offs were today we had to just focus on Hearts.
"We said that it would be unlikely that one team would win all five games based on how the league has gone this season. I did think if you could get the momentum and get a good start in your first split game, it sets you up for your next game.
"Just because you win this one, it doesn't make the next one any easier but I think psychologically this does us no harm. But we still need to perform. No one is going to give us it, don't rely on anyone else. It's all on us."
Your Site' Kris Boyd at Easter Road:
"Hearts have been at the top of the table for a long, long time now. They've got full belief in their manager to start with.
"The fans will always be there, they just want a team who goes out and represents them and they've had that this season.
"There have been people who have questioned Derek McInnes. His mindset, the way he's gone about it. But if you go and ask any of those Hearts players who they would have as their manager it would be Derek McInnes.
"Tony Bloom and the Jamestown analytics have taken a lot of credit and rightly so, but it still needs someone to have full belief and have full control of a dressing room because you can lose it.
"I see a team that's all together. You need players coming off the bench wanting to have an impact, not only in the match they're playing but to stake a claim the following week."
Hibernian head coach David Gray:
"The last two games we've beaten ourselves, in my opinion. The nine men that remained on the pitch from 48 minutes, gave absolutely everything, and didn't deserve that if I'm being honest. Because of how much they put into it, they defended their box incredibly.
"These are players that haven't played a lot of minutes, the goalkeeper [Smith] coming on and making big saves which you need. When you're down to nine men you need your goalie to make saves, you need to try and have a little bit of luck and ride your luck a little bit.
"And then when you look at the goals we lose, which makes it even tougher to take, the first one is a deflection and an own goal.
"Unfortunately I think both [red card] decisions are right. I think they're just mistakes, it's not through anything other than a mistake.
"The goalkeeper makes a decision rather than clearing it to take a touch, then obviously gets his bearings wrong. He's outside the box, marginally but he is.
"And then the second one from Felix, it's a mistake in the middle of the pitch, tries to atone for the mistake, overstretches, second yellow card. Pretty clear for me, and that's what's cost us the game."
