Benetton Treviso came within a whisker of recording their first GUINNESS PRO12 win of the season, as they drew 24-24 with Leinster.
Jayden Hayward missed a golden opportunity with four minutes remaining to put the Italians ahead with a penalty from 20m, but the hosts did at least manage a try bonus as Davide Giazzon, Andrea Pratichetti, Marco Barbini, and Dean Budd all went over.
A lacklustre Leinster - missing ten players to international duty - will feel lucky to escape from the Stadio Monigo with a try bonus, as Treviso were well worth the draw.
Ulster closed the gap at the top of the GUINNESS PRO12 as they inflicted the first defeat of the season on Ospreys, winning 25-16 at the Kingspan Stadium.
Ospreys had made their best ever start to a PRO12 season with seven wins from seven, but having also lost ten players to internationals Steve Tandy's men found themselves 18-3 down at the break.
And a second-half comeback - where the visitors got back to within a couple of points - was ended when Darren Cave crossed for his second score of the game in the last minute, handing Ulster their fourth league win in a row.
Last season's runners-up Glasgow Warriors slipped to their second defeat in three weeks, 19-9 at the Parc y Scarlets.
Steven Shingler kicked 14 points off the boot for Scarlets in the absence of Wales fly-half Rhys Priestland, and Rory Pitman came off the bench for the hosts to crash over for the decisive score late in the game.
Warriors now sit fourth in the table, while Scarlets' surge up the table continues having lost just one of their last six GUINNESS PRO12 encounters.
But it was not all bad news for the Scottish sides as Edinburgh recorded a comfortable 28-13 win over Cardiff Blues at BT Murrayfield.
Tries from Dougie Fife, Andries Strauss and Tom Brown earned Edinburgh their third win of the season, while Adam Thomas added a consolation score for the Blues.
Meanwhile, five tries for Munster meant they recorded a fourth straight win, beating Newport Gwent Dragons 38-12 away at Rodney Parade.
A perfect kicking display from fly-half Ian Keatley - who added 13 points from the tee - was joined by scores from Duncan Casey, Robin Copeland, Andrew Smith, Ronan O'Mahony and Paddy Butler as Munster claimed their fourth win in a row to move above Glasgow into third.
And Connacht were the other big winners of the weekend as they notched up a bonus-point 43-3 win over a sorry Zebre side at the Sportsground.
World Cup winner Mils Muliaina became the first-ever All Black to play for the Irish side and set up Danie Poolman to score the first of five tries as Zebre were blown away.
TRY OF THE WEEKEND
With Leinster struggling at 12-10 down to bottom of the table Zebre, Marco Barbini gave his side the boost they needed just after half-time with a sensational try.
The replacement hooker charged down Jimmy Gopperth's kick and showed an impressive turn of pace to gather the ball and cross brilliantly to the left of the posts.
BREAK OF THE WEEKEND
Man-of-the-match George Naoupu capped off a fine performance for Connacht in their 43-3 win over Zebre by setting up John Cooney for his side's fourth try.
Naoupu took advantage of the depleted Italian pack with a strong break down the right before handing on to Cooney who raced over in the corner.
PLAY OF THE WEEKEND
It may have been in vain but Glasgow Warriors' Chris Fusaro kept his side in the 19-9 loss to Scarlets thanks to this try-saving tackle.
Steve Shingler looked certain to go over in the left corner but Fusaro flew in and took advantage of the slippery conditions to prevent the centre scoring.
PLAYER OF THE WEEKEND
Darren Cave went over twice for Ulster in a man-of-the-match performance to see off Ospreys' late challenge.
After scoring in the tenth minute, the centre side-stepped a challenge and went over for his second try to secure the win with one minute left on the clock.
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