Steve Tandy says his Ospreys players will adopt a "cup final mentality" next week when they build towards a European showdown against Aviva Premiership high-fliers Exeter.
Substitute Sam Davies delivered a command performance as the Ospreys fought back superbly to floor French heavyweights Clermont Auvergne in stunning fashion at the Liberty Stadium.
Clermont led by seven points at half-time, and then the Ospreys lost their Wales fly-half star Dan Biggar through injury, but his replacement Davies took charge, kicking four penalties and a drop-goal following two earlier Biggar penalties.
Ospreys moved top of Pool Two as a result of their 21-13 victory, with Clermont not even collecting the consolation of a losing bonus point after centre Wesley Fofana's early try, plus eight points from scrum-half Morgan Parra's boot.
And it means that if the Ospreys beat Exeter at Sandy Park in nine days' time, they will win the group and secure a European Champions Cup quarter-final place.
"I am extremely proud of the players," head coach Tandy said.
"They battled throughout the game, and to come back from 13-6 down against a really experienced Clermont team who have got to how many finals in European rugby, was a real team effort.
"We probably haven't got as many glittering individuals as other European teams have got, but what we have got is a massive team ethic and a massive spirit in the group.
"There are not too many days that I have been prouder of this group, if I am honest.
"It has got to be up there with one of our best performances, but we still haven't achieved what we want to. We have got one more game to go, otherwise it will be all for nothing."
It looked as though it would be a frustrating night for the Ospreys, especially when Biggar limped off after 48 minutes.
Biggar, his right thigh heavily strapped and suffering from a dead leg, tried to run off the injury, but his attempts proved fruitless and the early exit will undoubtedly prove a concern for national coach Warren Gatland three weeks before this season's RBS 6 Nations Championship kicks off.
But nothing could take the gloss off a special night for the Ospreys as they extended a remarkable winning record against French opposition in Europe at the Liberty Stadium to 14 games.
Tandy said: "We were pretty calm at half-time. If we started getting flustered and forcing things, then the game can be taken away from you in an instant.
"But it was a huge effort, and the players deserve a massive pat on the back as a group for their performance.
"It is no good us getting really carried away, even though this is an amazing win for us and probably one of our finest, because it will count for nothing if we don't finish off the job in Exeter, which will be a tough ask.
"The boys have got two or three days off to recover, and then it will be a cup final mentality going down to Exeter."
Tandy also paid tribute to Davies, adding: "We didn't miss a beat when he went on. Nothing flusters him. He truly believes he can perform on any stage, which is a real positive."
And the Ospreys' Wales international flanker Justin Tipuric said: "In the past, we probably panicked a bit and tried to do things out of structure by going for a miracle pass or trying to create something out of nothing.
"But we stuck to what we know best tonight, stuck to our structure and didn't panic. We did the basics well and played in the right areas of the field."