Hearts' charge at the top of the Scottish Premiership was dealt a shock blow as Kilmarnock stunned the league leaders with a deserved victory at Rugby Park.

Michael Schjonning-Larsen's 17th-minute goal meant Hearts remain just two points ahead of Celtic at the top of the table with eight games to play, while the hosts are now level on points with 10th-placed St Mirren, who host Rangers on Sunday.

Kilmarnock showed intent from the start and could have gone ahead within the first five minutes.

Finlay Curtis controlled and turned on the edge of the Hearts box, his deflected strike hitting the base of the post and bouncing clear.

Schjonning-Larsen had already enjoyed a few forays up the park from his left-back position in the first quarter of an hour and he was the man who broke the deadlock.

The Estonian gave Michael Steinwender the slip to ghost in at the back post and meet Greg Kiltie's perfect cross, prodding past Alexander Schwolow.

Hearts were forced into a change when Tomas Magnusson went down with a head knock, replaced by Oisin McEntee.

Joe Hugill brought Schwolow into a diving save to prevent his side from going further behind, and Braga had another snap shot that went high and wide, but neither side could add to the scoreline before the break.

Derek McInnes brought on Islam Chesnokov on for Pierre Landry Kabore in the hope of sparking his side to life but Hearts continued to struggle to impose themselves on a home side eyeing a precious three points and defending with energy.

Hearts threw everything forward in search of a leveller but lacked a cutting edge and Kilmarnock kept their cool, looking to counter but prioritising defending their lead.

The hosts dealt with every question Hearts posed through the second half and six added minutes, celebrating what could be a vital in in the bid to beat the drop.

Hearts remain top but will be frustrated by a lacklustre performance and a missed opportunity to take another step towards the title.

Hearts took to the pitch at Rugby Park with Celtic breathing down their necks.

In recent weeks Derek McInnes' side had played before their title rivals, winning and putting pressure on those behind them to keep up.

A few hours before kick-off in Ayrshire, Celtic's 3-1 win over Motherwell has posed a question of the league leaders, reducing the gap at the top to just two points and challenging Hearts to reestablish the previous five-point gap.

It was a test they failed, unable to react to an early setback and looking like they were struggling for answers as Kilmarnock put up sturdy resistance.

Claudio Braga, so often the man who conjures up something special when needed, couldn't find the right finish and was often started of real service.

Questions will now be asked about Hearts as the split nears and their lead has been whittled down to two points.

The impending return of Cammy Devlin and Lawrence Shankland will provide a boost just when the team need it, but there's now little room for error if the team are to achieve the remarkable and lift the Premiership trophy.

Few would have given Kilmarnock much hope going into the game but a hard-fought win has given their bid for safety a massive boost at just the right time.

Schjonning-Larsen's goal will grab the headlines but it was a team performance that will delight Neil McCann.

Aaron Tshibola was a leader in midfield, involved in everything, and Finlay Curtis was a livewire, constantly posing a threat going forward.

A win over the side at the top of the pile will only boost confidence as games against the sides around them loom.

Next week's home match against bottom side Livingston now offers a huge opportunity to not only stretch the gap between Kilmarnock and the automatic relegation spot but results elsewhere could even see them climb out of the play-off spot.

Consistency has been an issue all season but a deserved win could start to build momentum at a crucial time.

Kilmarnock manager Neil McCann told BBC Scotland: "There's a lot to like. I'm so proud of the players. We've had two weeks to dwell on the Falkirk result.

"The message was to play with risk and bravery, but that we would have to match Hearts.

"We knew they would throw balls in the box and be physical, but to a man we were outstanding and thoroughly deserved the three points.

"We did all the stuff off the ball so well. Derek [McInnes] is a first-class manager and we had to adjust our tactics to respect how Hearts would play.

"We had everything tonight and could have scored more as well. We tried to stay composed, they stuck their chests out and deserve their victory.

"The bar was set when we came in - what we expect as a coaching team. What we're doing at home is so pleasing. I want it to become a fortress."

Hearts head coach Derek McInnes told BBC Scotland: "It wasn't good enough. I didn't think we started the game well, for whatever reason. We had a good week's work going into this game.

"I thought we had a good warm-up, looked sharp and ready then and when you come away from home against a team fighting for their lives you know what to expect.

"I didn't think we looked sharp enough to the pitch of the ball, didn't close spaces down or stop crosses. I just though we looked easy to play against.

"They get far too simplistic a goal and there's no pressure on the cross and they have a free man in the box.

"We gave Kilmarnock something to cling on to and you have to credit them.

"We had 60% possession and more chances but we never really… we huffed and puffed and had a few chances but you have to say Kilmarnock scrapped and fought for the three points.

"We tried to throw more attacking players on it but it petered out. We're disappointed not with our effort but the quality of our play.

"I've told the players we still wake up tomorrow top of the league with eight games to go. We pick ourselves up and go again."

Hearts are back in Premiership action when they host Dundee at Tynecastle on Saturday 21 March (15:00 GMT), while Kilmarnock welcome Livingston to Rugby Park at the same time.