Motherwell manager Stuart McCall said he witnessed "something special" as his side beat Scottish Premier League champions Celtic 3-1 at Fir Park.
Europa League qualifying ties are now a certainty for Motherwell in 2013/14.
"You demand energy and commitment, but some of the football was outstanding," McCall told BBC Radio Scotland.
"I normally say you have to score the first goal to win against the Old Firm; what character to go behind, come back and put in a performance like that."
Henrik Ojamaa's first-half strike, Michael Higdon's penalty and a Fraser Forster own-goal gave 'Well their second victory over Celtic at Fir Park this season.
And they will now play European football for the fifth year out of the last six.
"I could go through the team," McCall said. "There were some huge performances.
"I said to the lads 'enjoy that but don't get carried away with three games to go'. But they're special moments, to play as well as that against Celtic.
"It's a really proud moment. We beat Celtic a few years ago, 2-0. One was a mistake by them and one was a dodgy penalty, but today I thought we won in style.
"As a coach, as a person and as a player, you always want to try and improve.
"We looked at the points tally of 62 we got last season - the highest we've ever had in the SPL. We're on 60 now with three games to go. So I can't speak highly enough of the group of players we've got."
The North Lanarkshire outfit only need one more point to guarantee a second-place SPL finish.
Celtic, who made six changes to the team that clinched the SPL title against Inverness CT, went in front through Gary Hooper but Keith Lasley's expert pass enabled Ojamaa to level.
The Estonian then won his side a penalty after he was innocently clipped by Charlie Mulgrew, Higdon stepping up to convert his 26th goal of the season.
And Celtic's woes were complete when a misplaced Mikael Lustig headed clearance came off post then Forster for an own-goal.
"You can say they had people missing, but they bring international players in and I just think our lads were outstanding," added McCall.
"I think the fans should realise they've seen something special today.
"He [Lasley] is certainly not an unsung hero in our dressing room and he always seems to bring out his best against the best.
"That's what good players do; they try to raise their game when they're up against top quality."