Saracens beat Bath to secure top spot in the Aviva Premiership, Harlequins secured third spot and Leicester booked a home play-off semi-final.
Exeter beat Gloucester 40-39 in a thriller at Sandy Park as both sides qualified for next season's Heineken Cup.
London Welsh claimed a bonus-point win in their last game in the Aviva Premiership, beating Worcester 33-22 at Kassam Stadium.
Saracens confirmed top spot in the final Aviva Premiership table with a 23-14 win over Bath at Allianz Park.
Leicester Tigers ran in five tries as they beat London Irish 32-20 at Welford Road to secure a home Aviva Premiership semi-final next Saturday.
Defending champions Harlequins turned on the style to secure third place in the Aviva Premiership with a 22-19 win over Northampton.
Christian Wade took his tally to 13 Premiership tries but could not prevent Wasps from going down 21-20 to Sale at the Salford City Stadium.
Edinburgh posted only their seventh win of the season when they saw off Dragons 31-24 at Murrayfield in the final match of their PRO12 season.
The Lions have been warned that Australia will be looking to beat them on and off the field during this summer's tour Down Under.
Leinster rounded off the league phase of the RaboDirect PRO12 with a 37-19 win as the Ospreys relinquished their grip on the trophy.
Glasgow Warriors missed out on a home semi-final in the RaboDirect PRO12 despite a 20-3 win over Connacht on Friday evening.
Ulster have been crowned RaboDirect PRO12 league winners after finishing the regular season with a 37-13 victory over Cardiff Blues at Ravenhill.