Munster hammered Newport Gwent Dragons 45-17 to stay top of the Pro12 table but Dan Evans scored a hat-trick as Ospreys kept the pressure on by securing another win at Zebre on Friday.
Jaco Taute claimed a first-half double at Musgrave Park before Andrew Conway went over and a penalty try ensured the leaders had the bonus point in the bag at half-time.
Dave Kilcoyne and Ronan O'Mahony added further tries in the second half, with Tyler Bleyendaal scoring 15 points from the tee as Munster maintained their one-point advantage at the summit.
Ospreys are still breathing down Munster's necks after recovering from a poor start to dish out a 40-10 drubbing to bottom side Zebre and extend their winning run to 13 consecutive games in all competitions.
An early converted try from Tommaso Boni put Zebre 10-0 to the good, but the tide turned after Ashley Beck got Ospreys on the board.
It then turned into the Evans show, with the full-back helping himself to a treble within 10 minutes of the restart and Dafydd Howells getting in on the act with a superb solo effort.
Scarlets leapfrogged Glasgow Warriors to go fourth with a 26-14 success at Scotstoun, while sixth-placed Ulster scored four first-half tries to beat struggling Edinburgh 24-18 at at the Kingspan Stadium.