Leinster maintained their unbeaten league record with an 11th straight success in a hard-fought 22-19 win over Ospreys in Swansea.
Without the services of 18 players on Six Nations duties with Ireland, Leinster were far from their best, but dug in to repel a spirited performance from Ospreys.
Luke McGrath, Charlie Tector and Rabah Slimani scored their tries. Ciaran Frawley kicked a penalty and a conversion, with Ross Byrne adding a conversion.
Harri Deaves, Ethan Lewis and Cameron Jones scored Ospreys' tries, with Owen Williams and Jack Walsh each adding conversions.
Welsh hooker Sam Parry was a late withdrawal through illness and his side suffered a further setback when Leinster were first on the scoreboard.
With the first real attack of the game, the visitors exploited some poor defence from Ospreys to leave skipper McGrath with an unopposed run to the line.
Frawley missed the conversion but he was soon on target with a simple penalty as the Dublin-based side, aided by a strong scrum, increased their control on the match.
Ospreys suffered a further blow when scrum-half Reuben Morgan-Williams was forced to leave the field with an injury but they received a boost when Deaves finished off a driving line-out.
However, Leinster's response was swift, with Tector taking a short pass from McGrath to crash over for Frawley to convert and give the visitors a 15-7 half-time lead.
Ospreys lost Williams to a failed HIA but seven minutes after the restart, they reduced the arrears when hooker Lewis finished off a driving line-out but they could not maintain that momentum as Leinster replied with their third try.
A thumping tackle from Tommy O'Brien forced Keelan Giles to lose possession and the visitors made it count when Slimani crashed over from close range.
Giles immediately left the field for an HIA before a try from Jones set up a tense finish but Leinster just held on to remain unbeaten.
