Conference B leaders Munster dented Edinburgh's Champions Cup hopes while Connacht snapped their losing skid against Cardiff Blues.
The Scarlets overpowered Benetton while Ospreys completed a Welsh double over Italian opposition by beating Zebre.
Connacht 32-17 Cardiff Blues
Connacht ended a run of three successive PRO14 home defeats with a bonus-point win over Cardiff Blues at the Sportsground.
Rhys Carre's first-ever try for Cardiff looked an important score until Alex Wootton's quickfire brace just before half-time handed the hosts a 20-10 lead.
Corey Domachowski became the second Cardiff prop to touch down in the 64th minute, but Connacht captain Jarrad Butler and replacement Abraham Papali'i sewed up the result with final-quarter tries.
Edinburgh 10-22 Munster
Edinburgh's Champions Cup bid suffered another blow as they were overpowered by Munster at Murrayfield.
Richard Cockerill has refused to give up hope his capital outfit can clinch one of the three European places on offer from Conference B.
But time is running out for second-bottom Edinburgh to rescue the situation after their seventh defeat of a miserable campaign.
Munster's Jack O'Donoghue and Craig Casey gave the conference leaders a deserved half-time lead and while Bill Mata struck back for the Scots just after the break, it was the visitors who proved the more clinical as they added a third score through Gavin Coombes.
Edinburgh still have five games left to play but sit 11 points behind Scarlets in third, who have played two games more than Cockerill's side.
Scarlets 41-17 Benetton
Scarlets kept alive their hopes of qualifying for next season's Champions Cup with a comprehensive bonus-point victory over Benetton.
Jac Morgan crossed for two tries with Sam Costelow, Dane Blacker, Sione Kalamafoni and Paul Asquith also dotting down.
Dan Jones and Steff Evans combined for 11 points from the tee as the Scarlets snapped a three-game losing streak in style.
Leonardo Sarto and Cornelius Els scored Benetton's tries, both of which were converted by Edoardo Padovani, while a Tommaso Allan penalty opened the scoring at Parc y Scarlets.
Ospreys 10-0 Zebre
Ospreys inched to victory over Zebre at a wet Liberty Stadium.
Heavy drizzle made for difficult conditions and both teams produced constant errors, with the home side's discipline and ability to keep hold of the ball close to non-existent.
The only positive for Ospreys head coach Toby Booth was the win as it prevented Zebre doing the double over his team this season.
Josh Thomas kicked a penalty and there was a late try from man of the match Rhys Webb which Thomas improved as Zebre were kept scoreless.