Tomas Magnusson's 88th-minute strike sparked Tynecastle bedlam and gave Heart of Midlothian a crucial Edinburgh derby victory to extend their lead at the top of the Scottish Premiership table to six points.

It keeps Derek McInnes' side in the driving seat with second-top Rangers visiting fourth-top Motherwell while third-placed reigning champions Celtic host Livingston on Wednesday.

Another derby looked destined to have plenty of blood and thunder but no quality in the box as both sides struggled in front of goal during a fiery but nervous encounter.

Both were wasteful, getting themselves into good positions before squandering numerous chances at Tynecastle.

Islam Chesnokov, making his first Hearts start, missed the best chance for the hosts, the winger side-footing over from a narrow angle towards the end of the first half.

Meanwhile, Martin Boyle was the guilty party for the visitors, the forward lifting a shot over the bar after tenacious work from Nicky Cadden.

However, midfielder Magnusson struck as time looked to be running out as Hearts put last week's loss to St Mirren behind them to ensure they will have their noses in front of a resurgent Rangers when they visit Ibrox on Sunday.

The euphoric scenes at the end, from both Hearts fans and McInnes, painted a picture. An outpouring of emotion, of exultation after 88 minutes of sheer anxiety.

Hearts weren't great. Even the most ardent fan would admit that. At times, it seemed Hibs had their number.

Despite the attacking XI named by the head coach, there was a timidity up front.

With the spine of the team ripped out - Craig Halkett suspended, Cammy Devlin and Lawrence Shankland injured - players are yet to truly step up and fill their absence.

However, they came through it thanks to Magnusson's late goal. Harry Milne, impressive throughout, whipped a low ball in that the substitute poked home. Queue delirium.

This unlikely quest has been built on moments. Stuart Findlay's late goal at Tannadice. Alexandros Kyziridis' late goal at Almondvale. Halkett's winner in the last derby at Tynecastle. Craig Gordon's save at Dens Park.

This is another moment that will give the squad belief. Maybe, just maybe, it is their year.

It was a bold call from David Gray to chuck four winter signings straight into the derby. For a while, it looked like it might work.

The head coach had called for calmness in the chaos and they had that just a little more than their hosts. Midfielder Dan Barlaser, in particular, looked unaffected by the fervent atmosphere.

However, they lacked that bit of composure up top, with only one shot on target throughout the match.

What will perhaps sting most about this is that Hibs have arguably been the better side in all three derbies this season. They've won just one and they were hanging on at the end of this one.

They are only four points behind Motherwell, but Gray must now pick up his players from another gut-punch of a result. There are green shoots at least.

Hearts head coach Derek McInnes: "For all it was scrappy and untidy, that's the way derbies are. Without the experience we've got missing in the team, a lot of our boys were playing that type of game for the first time.

"I always feel we've got a goal in us. It's very rare we don't score. What a brilliant moment for us. Tynecastle was such a beautiful sight."

Hibs head coach David Gray: "Very little in it again. If anyone was going to win it, I felt it was going to be us. If you don't defend your box right until the end... That's what's cost us.

"The quality and big chances were slim, a draw would've probably been a fair result. We get nothing because we don't do the basics for the full duration of the game."

Hearts face Rangers on Sunday at Ibrox (16:30 GMT), while Hibs host St Mirren on Saturday (15:00).