Munster, Connacht and the Vodacom Bulls joined Leinster, the DHL Stormers, Ulster and Glasgow Warriors in the Final Eight with one round remaining.
The Stormers saw their 19-game winning streak in Cape Town ended by a 26-24 loss to Munster while Connacht overcame Cardiff 38-19.
An amazing game in Johannesburg saw the Bulls run in 11 tries as they beat Zebre Parma 78-12, with Edinburgh returning to winning ways with a 45-21 victory over the Ospreys.
Leaders Leinster came from behind to beat the Emirates Lions 39-36 with the final kick of the match to preserve their unbeaten run in the competition this season.
Round 17 began on Friday with the Cell C Sharks edging Benetton 43-33, Glasgow Warriors won a close battle with Scarlets 12-9 and Ulster eased past the Dragons 40-19.
Here, we recap how the Round 17 matches unfolded.
Cell C Sharks 43-33 Benetton
The Sharks won a thriller in Durban to all-but secure a play-off spot.
Tomas Albornoz converted tries from Sebastian Negri and Nacho Brex to put Benetton 14-0 ahead inside seven minutes but the Sharks were level at the break courtesy of tries from Vincent Tshituka and Grant Williams, with Curwin Bosch twice adding the extras.
Siya Kolisi, Williams and Makazole Mapimpi (2) added further scores after the break for the Sharks with Bosch posting a further nine points from the tee.
Joaquin Riera, Edoardo Padovani and Albornoz crossed for Benetton, who became the first Italian side to reach the semi-finals of a European tournament last week, with Albornoz adding two conversions.
Glasgow Warriors 12-9 Scarlets
Glasgow booked a home draw in the play-off quarter-finals on a wet and windy night at Scotstoun.
It will not go down as a classic but will be a valuable confidence boost ahead of these two teams meeting again in Llanelli in the last four of the EPCR Challenge Cup.
Scarlets dominated early on and led 6-0 thanks to two Dan Jones penalties but Sione Vailanu responded for the Warriors just before half-time.
Jones' third penalty of the night extended Scarlets' lead to 9-5 but Fraser Brown crossed for Glasgow, with Tom Jordan converting, which proved to be the last scoring action.
Ulster 40-19 Dragons
Hooker Tom Stewart claimed a second consecutive hat-trick in the URC to help Ulster to a six-try victory.
David McCann (Ulster) and Angus O'Brien traded early converted tries before Stewart went over twice, one converted by John Cooney, either side of Elliot Dee's yellow card for the visitors as the Irish province led 19-7 at the break.
Stewart claimed his hat-trick early in the second half, Nick Timoney also crossed and Ulster were awarded a penalty try too in the closing stages.
Dee and Rhodri Williams grabbed further tries for the Dragons, who finished the game with 14 players after Ashton Hewitt's yellow card.
Vodacom Bulls 78-12 Zebre Parma
The Bulls clinched a play-off spot with a comprehensive win in Johannesburg.
Wing Canan Moodie claimed a hat-trick as the Bulls scored 11 tries and fly-half Johan Goosen kicked 23 points.
Scrum-half Embrose Papier and lock forward Ruan Vermaak both crossed twice as Zebre wilted at altitude.
Gerhard Steenekamp, Marco van Staden, Bismarck du Plessis and Chris Smith completed the Bulls’ try rampage.
Zebre claimed consolation scores through Richard Kriel and Chris Cook.
Smith’s try in the final moments saw Bulls register the most points in a URC fixture, eclipsing the 75 the Ospreys managed against Benetton in February 2014.
Emirates Lions 36-39 Leinster
Leinster battled back from 15 points down to preserve their unbeaten URC record this season and secure a last-gasp victory.
It was a cruel ending for the Lions who were exciting in attack and crossed for tries through Edwill van der Merwe, Gianni Lombard, Marius Louw and Francke Horn as well as being awarded a penalty try.
Vakhtang Abdaladze, Liam Turner, Michael Milne, Rob Russell and Chris Cosgrave went over for Leinster as the Irish province secured a 16th win from 17 games.
Debutant Sam Prendergast helped himself to 14 points from the tee, including a penalty with the last kick of the game.
DHL Stormers 24-26 Munster
Munster ended Stormers’ 19-game winning streak in Cape Town.
Diarmuid Barron’s first-half brace, either side of Seabelo Senatla's sin-binning, put Munster in control before Frans Malherbe and Ruhan Nel crossed to make it 12-12 at the break.
Shane Daly's converted try put Munster back in front but their lead was reduced when skipper Steven Kitshoff went over with 15 minutes remaining.
Gavin Coombes’ late try, Ben Healy again adding the extras, secured a bonus point for Munster but Nel’s converted try from the final play ensured Stormers would leave with two bonus points.
Connacht 38-19 Cardiff
Connacht marked Andy Friend’s final home game as their director of rugby with a bonus-point win at the Sportsground which confirmed their place in the play-offs.
Connacht led 26-7 at half-time thanks to tries from Diarmuid Kilgallen, Diarmuid Tierney-Martin, Conor Oliver and Mack Hansen.
Thomas Young doubled Cardiff’s try tally in the 48th minute, adding to a Seb Davies effort, but a penalty try and a late score from Kieran Marmion wrapped up the result.
Despite Young squeezing in a last-minute try, Cardiff fell short of a bonus point ahead of their crunch Judgement Day clash with Ospreys next weekend.
Edinburgh 45-21 Ospreys
Edinburgh gave head coach Mike Blair a fitting send-off in his last home game before stepping down as they ended a run of four defeats.
Ben Vellacott, Dave Cherry, Sam Skinner, Emiliano Boffelli and Hamish Watson grabbed first-half tries, all converted by Boffelli, with Dewi Lake responding with a converted try for the Welsh side.
Skinner and Rhys Davies (Ospreys) were yellow-carded before Watson's try while Lake struck first in the second half for the visitors.
Darcy Graham added a brace for Edinburgh before Sam Parry's consolation with Ospreys' Morgan Morris also spending time in the sin-bin.