Ospreys closed in on a Guinness PRO12 semi-final spot with a convincing 24-10 victory over Ulster at the Liberty Stadium in Round 21 of the Guinness PRO12. The Welsh side went five points clear of their rivals in the league standings after first-half tries from Tom Habberfield and Tyler Ardron was followed up by a robust second-half defensive display. Replacement Brendon Leonard added Osprey’s third as they went in search of a bonus point but Ulster’s Jacob Stockdale responded in the dying minutes for the visitors but the damage was done. Ulster put pressure on the hosts from the off but Ospreys exited well, led by fly-half Dan Biggar, as they probed deep into Ulster territory. With just seven minutes gone, the ball squirted out the back of a scrum in the Ulster 22. Rhys Webb was on hand to pass to centre Ashley Beck who delivered a masterful offload around the back of Ulsterman Stuart McCloskey to winger Tom Habberfield who raced away into the corner for the opening score. Biggar added the extras from the touch line. But Ulster – fighting for a top-four place themselves – responded with some powerful running from Charles Piutau and Craig Gilroy with captain Rory Best taking a superb offload to bust through a tackle close to the Ospreys line. The Irish province were thwarted by a superb steal from flanker Justin Tipuric who arrived at the breakdown before any other player. The visitors continued to probe and were award a penalty soon after, fly-half Paddy Jackson slotted from 40 metres to put his side on the board after 20 minutes. Ospreys continued to edge possession in a game where both sides were visibly tense with a lot riding on the result, Biggar eased Ospreys’ nerves when he landed a long penalty to restore their seven-point lead. Moments before the break, Ospreys threatened the line after a superb break from centre Kieron Fonotia, the ball was recycled and Biggar’s long pass to Keelan Giles was almost intercepted by Luke Marshall only for the ball to go into touch. On the stroke of half-time Ospreys were finally rewarded for their sustained pressure. Full-back Dan Evans collected a long clearance and sliced through the Ulster defence at speed. He left Gilroy stranded as he passed to Habberfield who in turn found supporting lock Ardron who dived over under the sticks – Biggar slotted the conversion for a 17-3 lead at the break. The Ulstermen piled on the pressure after the break but the Ospreys defence stood firm during waves of attack on their own line and were rewarded with a turnover which deflated the Irish side. With a quarter of an hour to play, Ulster knew they had to act quickly to keep their semi-final prospects alive. Replacement Stockdale collected the ball on the wing – he fended Giles and beat Fonotia to come up just inches short of the line. Minutes later, the Irish side had a perfect attacking opportunity from a scrum but their passes just couldn’t stick and they gifted possession back to the Ospreys. And the Welsh side punished the visitors for their errors with replacement Leonard scooting over for Ospreys’ third try with five minutes to play. Straight from the restart, Stockdale found a dog leg in the Ospreys line to hit back immeditely and set up a grandstand finish with both sides seeking a bonus point. But replacement Sam Davies bravely collected a bouncing ball with Gilroy bearing down on him to see Ospreys home. Ulster now rely on other results to go their way to have any hope of qualifying for the semi-finals. The Guinness PRO12 Final takes place on May 27 at Aviva Stadium, Dublin. Fans can guarantee their place by booking their tickets via www.ticketmaster.ie Further information: www.pro12rugby.com/final