Celtic manager Neil Lennon said referee Willie Collum had had a "very poor game" after the Scottish champions were denied victory by Lewis Ferguson's added-on time penalty in a dramatic 3-3 draw at Aberdeen on Sunday.

Celtic, who came into the match on the back of successive defeats after a 2-0 loss to arch-rivals Rangers was followed by a 3-1 Europa League reverse against Serie A leaders AC Milan, twice came from behind only to be denied in stoppage time by the Dons.

A share of the spoils at Pittodrie left Lennon's side three points behind leaders Rangers, who could go six clear if they beat Livingston later on Sunday.

Ferguson opened the scoring with his first penalty two minutes before half-time in a behind closed doors contest but Callum McGregor equalised in the 52nd minute.

Aberdeen forward Ryan Hedges restored the hosts' lead in the 64th minute but Celtic substitute Leigh Griffiths equalised in the 75th minute and the Dons were reeling when the Hoops' Ryan Christie scored with a penalty two minutes later.

There was more spot-kick drama, however, when McGregor tripped Connor McLennan and Ferguson struck another precise penalty to give fourth-placed Aberdeen a point.

"I'm disappointed we haven't won it," Lennon told the BBC.

"We showed the character to come back twice and we then lose that late goal. Defensively, we were poor but attacking it was good, particularly in the second half. It's too sloppy defensively though."

Turning to Collum, the Hoops boss added: "I thought the referee had a very poor game today, decision making, being influenced by his assistants and some of his decisions were baffling."