Ten-man Rangers kept Celtic waiting to be crowned Scottish champions as the Ibrox side staged an incredible comeback from two goals down to snatch a last-gasp draw with Aberdeen at Pittodrie.

A Rangers defeat would have confirmed Celtic's fourth successive title, and it looked highly likely as the Dons raced ahead in the first half with a fine Leighton Clarkson free-kick and Pape Gueye strike.

With Ross McCausland sent off in between those goals for a second yellow after chopping down Topi Keskinen, Barry Ferguson's men had a mountain to climb.

But Hamza Igamane reduced the deficit in the 49th minute and, in a stunning finale, Ianis Hagi looped the ball into the net in the final seconds.

With just one defeat in nine games, Aberdeen took impressive form into this powderkeg fixture and knew a win would have returned them to third place.

Rangers, with one eye on the second leg of their Europa League quarter-final at Athletic Bilbao on Thursday, made nine changes and were skippered by former Dons midfielder Connor Barron.

The unfamiliar visiting side survived early let-offs when Shayden Morris fired narrowly wide after a great turn then Mats Knoester volleyed over from a few yards out.

But Aberdeen's pressure told when Clarkson curled a wonderful free-kick into the top corner from 20 yards.

And after McCausland's dismissal, Gueye tapped in from close range just before the break to double the home side's advantage.

Igamane had the ball in the net for Rangers in first-half added time, but it didn't count as Findlay Curtis was judged to have run the ball out of play in the build-up.

The Morocco striker wasn't to be denied, though, as he outmuscled the Aberdeen defence to reduce the deficit early in the second half.

That sparked a few jitters among the home support at a packed Pittodrie as, despite being a man down, Rangers started to make their mark in the game.

Curtis fluffed an effort from a good position while at the other end, Keskinen, Kevin Nisbet and Alexander Jensen sent shots wide.

Chances continued to come and Aberdeen thought they had restored their two-goal advantage when Nisbet smashed the ball into the net, but his goal was chalked off for a handball by the Millwall loanee.

And that was to prove crucial as Hagi levelled in the sixth and final minute of added time, following up with a fine finish after Cyriel Dessers had struck the post with a low drive, as Celtic's title champagne was put on ice.

The second-half collapse will sting for the Dons after they had all three points in their grasp and a numerical advantage.

Manager Jimmy Thelin will rue not fully punishing a side who have been struggling domestically and had continental matters on their minds.

But if a positive can be taken, it is that it does keep Aberdeen's momentum going – and not losing is a good habit to be in.

The Dons, who stay in fifth place, now behind Dundee United on goal difference, remain well placed to deliver on their European ambitions going into the split and will still fancy their chances of getting the job done.

Europe aside, this has been a season of few positives for Rangers. But this was a good point for Ferguson's side.

Amid incredibly bumpy domestic form, and sandwiched between the two legs of their Europa League quarter-final, many would have been expecting Rangers to falter again at Pittodrie.

They have been inconsistent and defensively brittle lately – and fell two goals down for the seventh time in 10 games.

But a makeshift side dug out an unlikely draw in the latest chapter of the club's Jekyll and Hyde season to remain unbeaten away from home in the league since December.

Aberdeen manager Jimmy Thelin: "It was tough for us, but we have to move on, we have an important game on Saturday in the [Scottish Cup] semi-final.

"In the second half it shouldn't happen but it can happen, they play more like a low block transition. We have time on the ball and instead of taking the initiative to attack more we play more sideways and backwards.'

Rangers manager Barry Ferguson: "After going to 10 men and 2-0 down you have to be pretty happy with getting a point.

"I want to win games but we are making it hard for ourselves with continually going down to 10 men. Maybe that is on me in terms of how I want us to approach it and be aggressive."