Harlequins director of rugby Conor O'Shea claimed that beating Toulouse on their own turf felt winning the Heineken Cup final.
But O'Shea has warned his players that despite the scale of the achievement - Quins became the first team to win a European tie at Toulouse in almost three years - it is only part of a learning curve.
A place in the quarter-finals is the target for the Aviva Premiership leaders, and that has become a more realistic goal after the 31-24 win on French soil, which moves the London side to just a point behind Pool Six leaders Toulouse.
Two tries from Mike Brown and one from Joe Gray, plus 16 points from the boot of Nick Evans, brought about the Harlequins win.
O'Shea said: "Right now this feels like we've won a cup final but it's a pool game and we have to make sure we keep learning.
"The resolve the players showed was incredible."
He added: "We won't stick our heads in the sand and say it was a perfect performance but these are the days that make the Heineken Cup and the games you are judged on."
Munster moved five points clear at the top of Pool One by beating Scarlets 19-13 but head coach Tony McGahan insists his side have plenty to do if they are to be involved in the business end of the competition.
McGahan said after the Thomond Park victory: "While we got through, we recognise we have a hell of a lot of work to do."
Northampton coach Jim Mallinder was delighted with his side as they claimed a first win of the season in the competition, 45-0 over Castres at Franklin's Gardens.
The home side blew Castres away with five tries in the final quarter to avenge their away defeat to the same opposition.
Northampton have no hope of progressing further in the Heineken Cup, but still face games against Munster and Scarlets in January.
Mallinder said: "That win gives us a chance to make it into the Amlin Challenge Cup but we will need a couple of good wins against those tough sides to have a chance of getting there."
On Saturday, Leicester rescued their European campaign by staging a superb second-half fightback against French heavyweights Clermont Auvergne to win 23-19 at Welford Road.
Leicester, Clermont and Ulster - comfortable 46-20 winners over Italian strugglers Aironi on Saturday - remain in the Pool Four shake-up with only one quarter-final place guaranteed.
"To qualify from these pools you need to win five of your six games," Leicester boss Richard Cockerill said.
"So we know exactly what we need to do, which is beat Ulster in Belfast and Aironi at home."
Also on Saturday, Leinster inflicted a 52-27 Pool Three defeat on shellshocked Bath - the English team's heaviest ever loss in the competition.
Leinster coach Joe Schmidt said: "We are obviously delighted to get the five points and with the way some of the tries were scored."
Glasgow drew 13-13 with Montpellier, while London Irish suffered a 25-19 home defeat to Racing Metro.