Leicester scraped into the Heineken Cup quarter-finals - and left Ospreys sweating on a last-eight place - despite losing an intense Liberty Stadium encounter.

Wales star James Hook kicked the Ospreys to victory with five penalties, but Leicester's losing bonus point meant they finished top of Pool Three.

Tigers look unlikely to secure a home quarter-final tie, though, while the Ospreys can now only progress as one of two best runners-up.

At the moment, they are handily placed, but games involving English clubs Wasps and Bath on Sunday could ultimately result in them being knocked out.

If the Ospreys survive, they could face an intriguing all-Welsh clash against Cardiff Blues in April.

All the Ospreys can do is play an agonising 24-hour waiting game, but Leicester have no such worries.

Derick Hougaard's penalty hat-trick proved sufficient to give them the point they required, as for the second time in Heineken Cup combat this season, Ospreys and Leicester played out a tryless game.

There was mixed news for the Ospreys involving two of their current Wales internationals, with full-back Lee Byrne ruled out through injury and lock Ian Gough agreeing a new two-year contract.

Byrne failed to recover in time from an ankle injury suffered last weekend, which will concern Wales boss Warren Gatland only a fortnight before his team launch their Six Nations title defence.

An Ospreys reshuffle saw Gavin Henson take the number 15 shirt, with Tommy Bowe moving into midfield alongside Andrew Bishop and Jonny Vaughton gaining a start on the wing.

Leicester were without injured trio Lewis Moody (ankle), Aaron Mauger (hamstring) and Dan Hipkiss (knee) as they targeted a quarter-final place.

The opening exchanges proved predictably fast and furious, with a simmering atmosphere between both packs requiring French referee Christophe Berdos' close attention.

Tigers' England prop Julian White was left bloodied - then bandaged - after an all-in wrestling match, before Hook built a useful lead by striking two long-range penalties.

Leicester took time to settle, but Hougaard cut the deficit through a 17th-minute penalty, but he then missed further penalty and drop-goal opportunities as Tigers edged the territorial battle.

Ospreys posed a threat when they moved possession wide, most of their attacking game initially being built around number eight Filo Tiatia's powerful surges.

And Leicester ended an attritional opening half reduced to 14 men when their England back Toby Flood was sin-binned for kicking Ospreys ball away from an offside position.

Flood could have no complaints about the decision, but the Ospreys stepped up pressure as half-time approached, with Shane Williams only narrowly denied a chip-and-chase try.

Tigers full-back Geordan Murphy was penalised for obstructing Williams, and Hook rifled a kick into the corner, setting up easily Ospreys' most threatening attacking position of the game.

Ryan Jones marshalled his forwards for a huge scrummaging effort five metres out, but his team were guilty of wasting two glorious chances.

Bishop knocked on Jones' pass with the line beckoning, and after Leicester struggled to clear, Henson then did not back himself following a clean break, cutting inside, where he found Leicester defenders waiting in abundance.

Ospreys would have been frustrated with only a three-point interval lead, but they began the second period in lively fashion.

Hook completed his penalty hat-trick, and then caused panic in Leicester's defence with a weaving run that had the Tigers retreating at a rate of knots.

Hook's raid on the Leicester 22 came from quick ball, something Ospreys had cried out for during the first half, and there were suddenly signs of gaps appearing.

Leicester, though, responded impressively, using their forwards to create threatening field position, and then keeping Ospreys pinned back through a well-executed tactical kicking game.

The Ospreys tried to bring Williams more into the contest, yet Hook remained their most probable scoring outlet, and a fourth penalty put Leicester 12-6 behind as he cancelled out Hougaard's second successful strike.

The penalty fest continued when Hougaard brought Leicester back to within three points, and Ospreys knew they somehow had to escape Tigers' suffocating presence.

Hook's fifth penalty restored a six-point lead with seven minutes remaining, piling the pressure on Leicester to remain within losing bonus-point range, and they managed it - just.