Derek McInnes said his Aberdeen side committed "hari-kari" with their defeat to Hearts, admitting that it will take a "dramatic collapse" from Celtic for the Dons to now win the title.

Simon Church converted Graeme Shinnie's third-minute cross as Aberdeen dominated the opening stages but they missed a series of chances and Juanma Delgado levelled on the rebound inside 32 minutes when Scott Brown failed to push Alim Ozturk's long-range strike to safety.

Aberdeen then shot themselves in the foot on the hour mark as they gave Premiership leaders Celtic the chance to move eight points clear at Motherwell on Saturday.

Kenny McLean hit a quick free-kick out of the park from the halfway line and Hearts took the throw while Shay Logan helped treat Ash Taylor for cramp. With two of the Dons back four out of commission, Hearts got the ball forward quickly and Jamie Walker crossed for Juanma to nod home.

The Dons boss all but admitted that the title race is now over, confessing that it would take a dramatic downturn from Celtic for the Pittodrie side to win the Premiership.

McInnes said: "The first half hour we were strong, aggressive, played with a lot of thought, played in the right areas, the front four's movement was really unnerving Hearts.

"But then we missed real good opportunities to get the second goal. It's important when you're hot you capitalise. And every chance you miss you give the opposition that encouragement. Hearts are too good an opponent to think 1-0 is going to be enough.

"To think of the chances we missed compared to that goal... It was poor to lose. Yes, he (Ozturk) could have been closed down better but it's a poor goal right across the board.

"After half-time I thought we were fine and just when we were considering making little adjustments to go and get the winner, we committed hari-kari. And Hearts punished it."

McInnes, who is hopeful skipper Ryan Jack is out for "weeks rather than months" after suffering a knee injury, added: "The game was actually a reference to where we are in the league.

"We put ourselves in a position to go and win it and crank it up, and we didn't. And we haven't done that in the league either.

"This was a real opportunity to put pressure on Celtic and show we are a team intent on challenging all the way.

"Although it's not mathematically impossible, we have gifted Celtic a less-pressured game.

"I would never say it's gone because that's a stupid thing to say, and I wouldn't expect my players to give it up. But it's an even bigger advantage to Celtic now. It's going to take a dramatic collapse from Celtic now."