Wasps beat the Newcastle Falcons 39-22, while there were also wins for Saracens, Exeter, Bath, Leicester and Northampton in the English Premiership.
With Exeter and Saracens having secured first and second place in the standings respectively last week, the match between Wasps and Newcastle in the last round was a straight shootout for third place. Finishing third would also book a match against Saracens instead of defending champions Exeter in the last four.
Playing at Kingston Park, Newcastle were favourites to win, but Wasps made a blistering start to blow that theory out of the water. The visitors, with flyhalf Danny Cipriani pulling the strings, raced out to a 19-3 lead thanks to three unanswered tries.
The Falcons fought back after the break with three tries of their own. But three more scores – including a scintillating effort from Willie le Loux – settled the result in Wasps favour.
Wasps will now face Saracens, who ran in nine tries for a 62-12 victory over Gloucester on Saturday, in the semi-finals in two weeks time.
Exeter demolished Harlequins 41-17, sending out a warning to their title rivals. The Chiefs will host Newcastle in the other semi-final.
In other notable results in the last round, club legend Matt Banahan scored a hat-trick in his last appearance for Bath in their 63-19 hammering of London Irish, the Leicester Tigers defeated the Sale Sharks 35-13 but just missed out on a place in the top four, and the Northampton Saints claimed a 32-24 win against the Worcester Warriors to finish their dismal campaign on a high.
Round 22 results:
Newcastle 22 Wasps 39
Saracens 62 Gloucester 12
Harlequins 17 Exeter Chiefs 41
Bath 63 London Irish 19
Sale Sharks 13 Leicester Tigers 35
Northampton Saints 32 Worcester Warriors 24
Exeter Chiefs vs Newcastle Falcons
Saracens vs Wasps