Leinster, who open their tilt for a fifth Heineken Champions crown at Racing 92 next Saturday, found themselves 22-10 down to the visitors in the all-Heineken Champions Cup clash at half-time and reduced to 14 men after Cian Healy’s red card in the 21st minute at the RDS Arena.

Ulster, who start their Heineken Champions Cup pool stage at Sale Sharks next Sunday, were dominant in the first half, scoring tries through Rob Herring, Kieran Treadwell and Ethan McIlroy, while only Ronan Kelleher replied for Leinster.

However, it was a different tale after the break as the URC leaders hit back strongly to notch their ninth win from nine games, Kelleher’s try being followed by a Garry Ringrose double and scores from Andrew Porter and James Lowe. Ross Byrne kicked 13 points.

In Saturday’s other URC games, there were victories over EPCR Challenge Cup opposition for two South African sides making their Heineken Champions Cup debuts next week, DHL Stormers overcoming Dragons 34-26 and Vodacom Bulls routing Cardiff Rugby 45-9.

In the Gallagher Premiership, Gloucester Rugby ended their three-game losing streak ahead of their Heineken Champions Cup Pool A opener at home to Union Bordeaux-Bègles next Saturday with a 34-19 bonus-point win against Pool B team Northampton Saints at Kingsholm Stadium.

Gloucester took the lead through Jack Singleton, but Northampton, who travel to Stade Rochelais next Saturday, struck back to nudge ahead with a five-minute Tommy Freeman try double.

However, Gloucester soon took control when Chris Harris crossed and he was followed over by Santiago Carreras and Fraser Balmain to give the home side a comfortable lead.

Despite a late James Ramm try for Northampton, Carreras kicked two penalties and all four conversions to ensure Gloucester held on to win.

Other Premiership action saw London Irish pick up their second win of the season with a 39-17 home victory over Newcastle Falcons, while fellow Heineken Champions Cup Pool B side Leicester Tigers were held 26-26 at Bristol Bears.

In the TOP 14, ASM Clermont Auvergne halted a run of three defeats with 19-14 home victory over Heineken Champions Cup Pool B rivals Montpellier Hérault Rugby.

Loïc Godener’s try cancelled out an early score from George Bridge and the boot of Jules Plisson was subsequently key to Clermont’s success.

In other TOP 14 games involving Heineken Champions Cup teams, Union Bordeaux-Bègles defeated CA Brive 33-13 and Stade Toulousain beat USAP 34-13, but Lyon crashed 19-7 at Aviron Bayonnais and Stade Rochelais went down 27-14 at Stade Français Paris.

Leinster Rugby, runners-up in last season’s Heineken Champions Cup, warmed up for this term’s competition in style on Saturday by completing a stunning 38-29 comeback victory over Ulster Rugby in the United Rugby Championship.