Italy deservedly led Ireland 16-12 at half-time in Rome, but Joe Schmidt's side just about did enough to avoid a huge Six Nations upset.
Worcester Warriors eased their relegation fears with a third victory of the season over Leicester Tigers, who have lost five in a row.
The Scarlets ran in six tries to mark Leigh Halfpenny's long-awaited return with a 43-21 thrashing of the Cheetahs in Pro14 on Sunday.
The Jaguares opened their 2019 account thanks to Rodrigo Bruni and Bautista Delguy in Buenos Aires on Saturday.
Zack Holmes scored 15 points as Toulouse extended their lead at the Top 14 summit, while Stade Francais boosted their play-off hopes.
Luca Sperandio and Niccolo Cannone scored two tries apiece as Benetton Treviso stretched their unbeaten run to eight games.
Warren Gatland hailed his "special" Wales players after they claimed a record 12th consecutive win at the expense of England.
England's defeat to Wales in the Six Nations was decided by "small margins" and their ill-discipline proved costly, says Eddie Jones.
There was late drama for the Stormers against the Lions, while the Sharks were decidedly more comfortable against the Blues in Super Rugby.
Wales came from 10-3 down at half-time to claim a record 12th consecutive victory and go top of the Six Nations table.
Saracens' defeat on Friday left the door ajar for Exeter Chiefs, who downed Newcastle Falcons to go top of the Premiership.
Having been thrashed by England last time out, a much-changed France side produced a fine showing to down Scotland in Paris.
Peter O'Mahony is relishing the prospect of leading Ireland out in Rome in the absence of the rested Rory Best.
New Zealand pair Richie Mo'unga and Scott Barrett scored two tries each in a convincing win for the Crusaders.
Ben Morgan's brace led Gloucester to another big victory as they fended off a fast-finishing Saracens.
Glasgow Warriors closed the gap on Munster at the top of Conference A, despite both recording wins in the latest round of Pro14 fixtures.