The Scarlets also got back to winning ways with 20-year-old fly-half Owen Williams catching the eye while Newport Gwent Dragons showed great character to bounce back and defeat Treviso.
Here we review all the weekend's best action.
TRY OF THE WEEKEND
The stand-out try of the RaboDirect PRO12 weekend came from the unlikeliest of sources in the shape of Ospreys prop Ryan Bevington.
Bevington finished off a superb team effort, finishing off from all of 40 metres after a fine breakaway from Ospreys to score the only try of the match and inflict a first RaboDirect PRO12 home defeat of the season on Ulster.
Centre Jonathan Spratt made the initial break from deep inside his own half and he fed impressive scrum-half Kahn Fotuali'i, who had the presence of mind to spot Bevington on the inside.
Bevington still had plenty of work to do but he had the legs to finish off the try.
BREAK OF THE WEEKEND
A breath-taking start to the match between Zebre and Glasgow Warriors on Sunday saw both sides score two tries each within the first 11 minutes.
Byron McGuigan and Alex Dunbar each responded to scores from Zebre Dries van Schalkwyk and Tito Tebaldi, but it was the South Africa-born No.8 who lit the touch paper.
Van Schalkwyk intercepted Nikola Matawalu's loose pass and he romped clear to give Zebre early hope of a first RaboDirect PRO12 of the season.
Matawalu responded to deliver a man-of-the-match performance and secure victory for Glasgow, but van Schalkwyk's break ensured a try-fest in northern Italy.
PLAY OF THE WEEKEND
For sheer stubbornness and character, Steffan Jones of Newport Gwent Dragons earns this week's play of the weekend for his try that was crucial in seeing off Treviso on Friday night.
Jones endured a torrid night with the boot, missing numerous opportunities from the tee as Treviso marched into a 14-6 lead at half-time.
But Jones seized the bull by the horns and redeemed himself in the second half, bursting through from 25 metres to get his side back into the game.
Tom Prydie took over kicking duties and grabbed a try of his own but with Jones' score early in the second half, the Dragons may have been done for.
PLAYER OF THE WEEKEND
With a host of players missing on international duty, a number of youngsters were giving their chance to shine.
Owen Williams performed admirably at fly-half for the Scarlets while Ian Madigan again staked a claim to be handed more responsibly when Jonny Sexton departs Leinster.
But Munster's Ian Keatley again proved himself Mr Reliable to help his side recover from their shock home win to Cardiff Blues last time out in the RaboDirect PRO12.
Keatley, who ultimately finished with 20 points, kept the scoreboard ticking over before the floodgates opened in a 30-3 win. He has just two Ireland caps but he continues to ensure Ronan O'Gara's absence is no problem for Rob Penney's side.
LIONS WATCH
Alun Wyn Jones came off the bench in Ospreys' fine win at Ulster after 49 minutes and already there are calls for him to start for Wales against Italy a week on Saturday.
The 27-year-old featured in all three Lions tests in 2009 and if makes an impact for Wales in the remainder of the Six Nations, he could well find his way onto the plane to Australia.
And while Michael Bent may have been thrown into the international set-up somewhat early upon his arrival from New Zealand, he continues to find his feet in the Leinster front-row.
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