John Cooney slotted over a last-gasp long-range penalty to earn Ulster a 23-21 win over Leinster and guarantee them a place in the United Rugby Championship play-offs.
Leinster have decided to rest many of their frontline players to take on Ulster on Saturday at the Kingspan Stadium, with one eye on the Investec Champions Cup next weekend.
Jordan Larmour scored his first senior hat-trick for Leinster as the Irish province produced a second-half masterclass to hammer Ospreys 61-14 at the RDS.
Leinster player rating: After their statement win against La Rochelle, Leinster were brought down to earth with a bump in Johannesburg. In a humbling match for Leinster against the Lions in the URC, here's how the players rated:
Leinster are sweating over the fitness of Cian Healy ahead of their Investec Champions Cup quarter-final against current holders La Rochelle on Saturday at the Aviva Stadium.
Leinster head coach Leo Cullen has issued an injury update as his side's preparations for the upcoming Investec Champions Cup Round of 16 match against Leicester Tigers at Aviva Stadium heat up.
The Irish province took over pole position in the group with a hard-fought 37-27 win over Sale in Dublin.
Leinster player ratings: A sleepy and error-ridden start for Leinster saw an under-strength Sale Sharks stake an early claim at the RDS, but the home side eventually came good, with a bonus point into the bargain on a 37-27 scoreline.
Leinster has confirmed its lineup for the upcoming Champions Cup clash against La Rochelle, with Harry Byrne winning the race for the pivotal flyhalf position.