Glasgow Warriors surrendered their place at the top of the Guinness PRO 12 table to Ospreys at the Liberty Stadium last night after crashing to a 21-10 defeat.

The result means that if the Welsh team hold on to one of the top two places after their final game in Connacht next weekend, they will secure a home draw in the play-off semi-final.

Both teams had already secured their places in the end-of-season play-offs.

Ospreys, who had not beaten Glasgow in their seven previous attempts, were indebted to tries from centre Ben John and scrum-half Rhys Webb. Glasgow's try came from flanker Chris Fusaro.

The hosts named Wales flanker Dan Lydiate on the replacements bench, with James King being favoured on the blindside flank. Glasgow made five changes from the team that beat Connacht - including Duncan Weir, who replaced Finn Russell at fly-half. The other changes were in the pack.

Ultimately Ospreys won well but the first half was very keenly contested and ended with the teams locked at 3-3.

With so much riding on the game, the opportunity for points was at a premium early on but Ospreys made a bright start when man of the match Josh Matavesi sent Tyler Ardron on a run into the Glasgow 22.

The first chance of points came when Ardron was penalised at a line-out but Duncan Weir failed to take advantage as his kick went the wrong side of the right upright.

Dangerous runner Niko Matawalu started a 70-metre counter-attack which resulted in a penalty, successfully kicked by Weir in the 15th minute to give the visitors a 3-0 lead.

Ospreys responded well with a move from a line-out which saw Dan Biggar cross the line - however the try was disallowed on the intervention of the TV match official, Derek Bevan.

Biggar was then forced from the field for a head injury assessment - and while he was off the pitch the home side levelled the scores with Dan Evans kicking a 21st-minute penalty.

After Glasgow had a half-chance of a try dashed when Matawalu failed to control his kick ahead, they earned a penalty in their own half - but Stuart Hogg was off target with his 55-metre effort.

Biggar returned to the field but he was wayward with a drop-goal attempt - the final kick of the half.

Ospreys started the second half in positive mood, earning a penalty after only three minutes which was successfully kicked by Biggar.

After Ospreys soaked up some serious pressure they went up the other end and scored the game's first try through Ben John, who was on the end of a fine inside pass from Matavesi. The effort went unconverted.

Glasgow's cause was not helped when Weir missed a short-range penalty as heavy rain started falling.

With their tails up Ospreys scored a second try on the hour mark when a well-worked line-out sent Webb on a dash for the line - and after a neat chip and collect the scrum-half went over. Biggar's conversion gave Ospreys an 18-3 lead.

Glasgow were not finished and they responded four minutes later with a converted try for Fusaro from a line-out drive. Weir's conversion made for an interesting final 15 minutes.

However, the pressure on the Ospreys was eased when Biggar kicked his second penalty of the contest five minutes from time to open up an 11-point advantage - ultimately denying Glasgow a crucial bonus point.