Ospreys (16) 37
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Highlights: Ospreys 37-22 Worcester
Tries: Walker, Henson, Williams, Bowe Cons: Hook Pens: Hook 5
Worcester (6) 22
Tries: Tuitupou Cons: Jones Pens: Jones 5
The Ospreys eventually clinched a crucial home victory over Worcester to put themselves in reach of the EDF Energy Cup semi-finals.
They ran out 37-22 winners against the the visiting Warriors outscoring their opponents four tries to one at the Liberty Stadium.
Nikki Walker, Gavin Henson, Shane Williams and Tommy Bowe all scored.
Visiting fly-half Matthew Jones scored 17 points on his return to his former region with a perfect kicking display.
Worcester had the best of the opening 20 minutes with former Australia international Chris Latham in thick of the action.
Fellow Warrior and former Ospreys outside half Matthew Jones then came to the fore on his return to face his former employers.
Following a mix up between the home side's backline his kick-and-chase up field nearly led to the opening score after eight minutes.
Only some excellent covering by Ospreys wing Nikki Walker stopped him from scoring with two metres to the tryline.
A few minutes later the 24-year-old fly-half did succeed in opening the scoring with a 15th minute penalty from just outside the 22 to make it 3-0 to the visitors.
However, the home side were back level within two minutes when James Hook levelled the game at 3-3 after the Warriors were caught on the wrong side of the ball.
The game settled down with Jones continuing in the spotlight when he was harshly sin-binned on 19 minutes for not releasing the ball at the break down.
With the Welshman off the field the Warriors lost some direction but the Ospreys failed to immediately capitalise on the visitor's backline confusion.
But yet another penalty for killing the ball by Worcester handed them a 6-3 advantage on 27 minutes with a second Hook kick.
In the immediate aftermath, the ever-involved Latham seemed to block the increasingly dangerous Shane Williams in the centre of the field as he attempted a chip and chase over the Warriors defence.
The Ospreys picked up the ball from the attempted clearance with the ball breaking to Duncan Jones who failed to take advantage of his side's four-strong overlap.
The recycled ball soon made it back out to the wing for Walker to cross on 30 minutes, however, Hook failed with the subsequent conversion to keep the score at 11-3.
With Jones back on the field he was handed an instant chance to make up for his missing minutes with his second well-struck penalty of the afternoon bringing the scores back to 11-6 on 33 minutes.
Then with less than 10 minutes to go to the interval, the Ospreys backline kicked into gear with only a last-ditch Alex Grove tackle preventing Williams from side-stepping his was through for what would have been a spectacular score.
A similar Filo Tiatia was cut short minutes later with the line begging before the home side's pressure told on 39 minutes with Gavin Henson coolly leaving Latham for dead in midfield with a side step and run in next to the posts to make it 16-6 at the half.
The opening minute of the second half handed Jones another easy opportunity to score and he made it 15-9 after yet another infringement at the ruck.
But any potential comeback did not last long with the ball worked back up field by the Ospreys and patiently worked through the backs to Williams for an easy score on 43 minutes to make it 21-9
Hook's conversion made it 23-9 before another Jones penalty on 47 minutes kept the Warriors just in touch at 23-12.
With the Ospreys seemingly in control, flanker Tom Smith was adjudged to have offended at the ruck and sin-binned on 51 minutes.
Worcester almost immediately took advantage of their extra man with centre Sam Tuitupou powering over the line, with replacement scrum-half Jamie Nutbrown in tow, on 54 minutes.
A successful Jones conversion made it 23-19 but Hook kept his side's slight advantage with a 58th minute penalty to make it 26-19.
The English side killed the ball again to hand Hook another penalty on 62 minutes and any chance of a comeback disappeared as he made it 29-19 with only a quarter of the game to go.
Jones and Hook again swapped penalties to make it take the scores to 32-22 on 74 minutes.
With victory all but assured the home side then went in search of a bonus point with centre Tommy Bowe duly obliging on on 81 minutes with diagonal run to the corner to make the final margin 37-22.
The Ospreys now have the opportunity to win their group and secure a semi-final spot if they can beat London Irish at the Madejski Stadium next Sunday.
Ospreys: Byrne; Walker, Bowe, Henson, Williams; Hook, Webb; D. Jones (capt), Millward, Gough, Hibbard, Bateman, Smith, Tandy, Tiatia.
Replacements: Nutbrown for Webb (47), A. Jones for Millward (54), Shervington for Hibbard (74), Wyn-Jones for Bateman (59), R. Jones for Smith (66).
Not used: Biggar, A. Bishop.
Sin Bin: Smith (51)
Warriors: Latham; Pennell, Grove, Tuitupou, Fellows; Jones, R. Powell; Mullan, Lutui, Taumoepeau, Rawlinson (capt), Gillies, Cox, Abbott, Talei.
Replacements: Wheatcroft for Latham (72), M. Powell for R. Powell (67), Morris for Mullan (72), Ruwers for Lutui (72).
Not used: Kitchener, R. Wood, Carlisle.
Sin Bin: Jones (19)
Referee: David Rose (RFU)