Kenny Miller reluctantly admits Celtic have been scintillating this season.
But the Rangers hero says Ange Postecoglou and his troops still have to do the hard bit after accelerating away from the champions.
A 2-1 victory at Ibrox secured Celtic's first win at Ibrox since 2019 and crucially moved them six points clear at the top.
They have one hand on the title heading into the final six games and it would take an almighty collapse not to win it from here.
For Gers the focus shifts to the Europa League and the Scottish Cup. They're in the latter stages of both with a Euro quarter-final with Braga to kick off on Thursday while they face Celtic at Hampden in two weeks' time.
And Miller, who played on both sides of the Glasgow divide but is best remembered for his three spells at Ibrox, has urged Gio van Bronckhorst 's team to refocus and book their place in the Europa League last four.
But he insists the Premiership title race isn't completely over until Celtic mathematically win it - warning Postecoglou's side the hardest part is yet to come.
He said on talkSPORT: "Their European performances have been a standout. The Dortmund one especially, going toe to toe with one of the best teams in Europe, and coming out in top over the two legs.
"They followed that up with an impressive performance against Red Star. So it's a big opportunity to get into a European semi-final.
"The lads will be hurting after the result but it wasn't a bad performance. Celtic defended very well in the second half.
"They have to refocus onto Thursday night and you just never know. As much as we're saying it's going to be a long way back, the hardest thing to do when you're going for the league is to get it over the line.
"It's a tough thing to do because the pressure is on.
"Also the opposition think 'we don't want them to win it against us.'
"You never know, so it's important Rangers get back to where they were, rest up, recover and get ready to go again."
Miller reckons the Scottish Cup is Rangers' only "realistic" chance of silverware with the Premiership now out of their hands while Europa League glory is still a distant ambition.
He gave credit to Celtic for the football they've played but urged Gers to beat them at Hampden on 17 April and finish the season with at least one trophy.
Miller went on: "Some of the football they've played - as a Rangers fan it's hard to say this - but it's been good to watch.
"They've come unstuck in certain games where teams have made it hard for them and been hard to break down.
"But over the piece, they won the fist trophy in December in the League Cup and what a massive game in two weeks time, the Old Firm semi-final.
"It's so big for so many reasons. You've got Ange who's done phenomenal since he's come in, he's been a breath of fresh air for Scottish football as well.
"You've got his Celtic team going for a potential treble, and you've got Rangers looking to get the only bit of silverware that's realistic for them this year.
"They've got the opportunity to stop that treble. In two weeks' time, it's a monumental game."
