Forrest's 29th-minute cross was bundled home as Bayo competed with Christophe Berra and the striker was on hand again on the hour mark after Ajer's low delivery was swept home as the forward challenged with Craig Halkett.

Bayo later headed against the post before going off with cramp.

Lennon said: "We were a bit slow to get the ball into him early but once he found his feet in the game he was superb and should have had a hat-trick. I have told him that as well.

"His forte is getting on the end of crosses and he's unlucky, he hit the post with a header, but he can be absolutely delighted, and we all are with him as well.

"I love the second goal. It's a real striker's goal, getting across the defender. It's an absolutely wonderful finish.

"He had a real bad hamstring injury and that kept him out from March onwards. Then he had a decent pre-season and the hamstring recurred. So he has had to be patient with the injury and his rehabilitation.

"We just felt Odsonne (Edouard) looked very fatigued on Thursday and he has a bit of a hand injury, and it was a good opportunity to showcase Bayo, see what he could do in that environment, and he excelled."

Bayo said: "I touched the ball for the first one. The defender also touched the ball but I got the last touch. I scored two goals."

However, Hearts manager Levein said: "I'm very frustrated. We scored two own goals and gifted Celtic the third goal. They had five shots on goal in the match so I'm sitting here feeling we have shot ourselves in the foot.

"Celtic don't need a hand when it comes to scoring goals and clearly that's what we did. Christophe said it hit his hip, Halks said it went in off his toe. I have watched it and I agree with the boys.

"You have got to credit the striker with getting into the area and such like, but the facts are they were own goals.

"But it doesn't actually matter, my point was we have assisted Celtic in their attempts to score goals."

Callum McGregor netted the second from 25 yards in the 54th minute but Levein was disappointed Loic Damour had lost possession seconds earlier.

Meanwhile, Lennon is hopeful of bringing in new players ahead of the last full week of the transfer window.

"We need players in in two or three positions," said Lennon, whose new signing Fraser Forster saved a late penalty before Conor Washington netted the rebound.

"That's been ongoing for quite a while. Hopefully, we can get some quality bodies in Monday or Tuesday. If we do I'd like to take them to Sweden to get them integrated if they have got an opportunity to play (against Rangers) next weekend."