Defending champions Stade Toulousain were fortunate to avoid a potentially damaging home defeat by London Wasps after a late Dave Walder penalty just drifted wide.

As it was, the hosts probably deserved their 18-16 win, but they made life complicated for themselves with a string of poor choices and handling errors. The inclement weather certainly didn't help, but ultimately the four-time champions were delighted that fly-half David Skrela had his kicking boots on after his six successful penalties sealed their nervy win.

Skrela and Walder landed three kicks apiece as the error-strewn first half ended 9-9, but it appeared that Toulouse were heading for a comfortable win when they then moved six points clear after two further penalties early in the second period.

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But the match was turned on its head when television replays showed David Lemi had done just enough to exert downward pressure and claim the game's only try with just 15 minutes remaining. When Walder nonchalantly kicked the conversion it looked like a massive upset could be on the cards, only for Skrela's sixth success to squeeze the hosts back into the lead in the 72nd minute.

That should have been that for the experienced home side, but yet another penalty was conceded two minutes from time - when Census Johnston killed the ball - only for Walder to falter at the crucial moment.

Heineken Cup runners-up Biarritz Olympic, meanwhile, begun their 2010/11 campaign with a crucial 11-12 away win at Bath in Pool 4. International scrum-half Dimitri Yachvili was the architect of their victory, kicking four penalties to secure the Basques a invaluable away win.

Bath started the brightly, with early pressure bringing two penalties in the first five minutes - the latter of which Ollie Barkley successfully kicked over to give them a 3-0 lead. Two minutes later that was up to 8-0 when South African scrum-half Michael Claassens touched down in the corner after being fed by Matthew Carraro following another dominant scrum.

Barkley missed his attempted conversion from the corner and the score remained 8-0 up to half time as Biarritz defended stoutly.

The fight-back then began just two minutes after the restart as Yachvili was on target with his first penalty attempt of the afternoon. He went on to slot further efforts in the 49th and 56th minutes as the visitors' growing confidence (and pressure) began to reap dividends.

Fly-half Julien Peyrelongue missed with an attempted drop-goal just after the hour mark, and then - significantly for Biarritz - gave way to Damien Traille as the French international entered the playing field for the first time since last season's Heineken Cup quarter-finals.

But the lead switched back to Bath soon after when Barkley kicked his second penalty of the afternoon, only for ill-discipline from England prop Dave Wilson to cost the home side dear on 71 minutes. The resultant yellow card immediately put Bath at a numerical disadvantage, while Yachvili's calm slotting of the penalty put Biarritz 11-12 ahead with eight minutes remaining.

Bath piled on the pressure in the closing minutes as they looked desperately for the winning score, but Biarritz defended with irresistible lustre, led by their indomitable captain Imanol Harinordoquy.

The victory was particularly sweet for Biarritz winger Iain Balshaw, who spent seven seasons at Bath between 1997-2004.

England winger Paul Sackey scored a 77th-minute try - his first for Toulon - to help the French side beat Opsreys 19-14 on their long-awaited Heineken Cup debut on Saturday.

Sackey has had a difficult settling in period for Toulon since joining from London Wasps in the summer, but his match-winning effort against Ospreys should give him just the boost he needs.

Fellow England international Jonny Wilkinson kicked the resultant conversion, to add to four earlier penalties as the home side rallied from 9-14 down with just seven minutes remaining at a heaving Stade Félix Mayol.

The win was just the start Toulon wanted in Pool 1 as they hope to make a serious impact on their debut in Europe's top club competition.

Philippe Saint-André's side - who were playing in a new-look blue shirt - are currently joint second in Top 14 and came into this match on the back of four successive wins. They also had the experience of reaching last season's Amlin Challenge Cup final under their belts, while their star-studded side packed enough international talent to scare most sides. They had to make do without several stars, however, with scrum-half Pierre Mignoni and flanker Joe Van Niekerk both picking up training injuries during the week, while Carl Hayman and Felipe Contepomi were both left out due to the regulation limiting sides to two non-EU players.

The first half was a typically tight affair with both sides tied at 6-6 after a brace of penalties each from Wilkinson and Dan Biggar. Toulon were resilient and forceful in defence but try-scoring opportunities were at a premium for both teams.

Wilkinson and Biggar traded one more penalty each after the restart before the deadlock was finally broken on the hour when Shane Williams - once a target for Toulon - showed his class with an individual try down the flank.

Biggar missed the conversion, however, paving the way for Toulon's late rally, which started with Wilkinson's 73rd-minute penalty and culminated four minutes later with Sackey's match-winning try. 

Heineken Cup Pools & Fixtures / Leading point and try-scorers

Top 14 leaders Racing-Métro 92 also made their Heineken Cup debut on Saturday afternoon, although theirs was a less happy entrance as they went down 38-22 away to 2009 winners Leinster.

The Parisians were outscored by five tries to one, with Fijian Albert Vul Vuli getting their consolation effort 15 minutes into the second half. His lone try briefly gave Racing hope as they moved to within seven points of Leinster (26-19), before the hosts added two later tries (through Jamie Heaslip and Fergus McFadden) to seal the win.

Earlier, first-half tries from Sean O'Brien and Robert Kearney helped Leinster to a 21-6 lead at the break, with Racing's points coming via a penalty each from fly-half Jérôme Fillol and full-back Francois Steyn.

Fillol added a second straight after the restart, but Racing then went down to 14 men when scrum-half Nicolas Durand was sin-binned, paving the way for Richardt Conrad-Strauss to score Leinster's third try of the afternoon.

Perpignan also ended up on the losing side, despite outscoring their hosts Scarlets by five tries to four. The Catalans went down 43-34 at the Parc y Scarlets in a hugely entertaining Pool 5 match that swung one way and then the other. Ultimately, however, they were undone by the boot of Stephen Jones as the Welsh international kicked four penalties and conversions to add his own try, to end with an impressive match haul of 25 points.

Jones began the afternoon's point-fest with his second-minute penalty, but Perpignan then replied in dramatic style with Jean-Philippe Grandclaude and Julien Candelon both going over for tries inside the first quarter of an hour. Jérôme Porical added one of the two conversions to put Perpignan 6-12 up, before somewhat blotting his copybook by getting sin-binned just before the half hour.

Scarlets were back within three points by then thanks to two more Jones penalties, and they went on to claim a 26-15 half-time lead after full-back Rhys Priestland touched down twice in four minutes before the break.

The home side continued that momentum after the break by adding two more tries in the first six minutes of the second half - with Regan King and Jones himself going over. Jones converted all four tries to make it an incredible 28-point burst in just 11 minutes. At that stage Perpignan had seen a one-time 6-12 lead turned into a massive 40-15 deficit.

But the Catalans weren't done yet and managed to get some momentum of their own following Adrien Plante's 54th-minute try. Jonathon Fa'amatuainu's 67th-minute yellow card helped their cause further, with Ovidiu Tonita (69th min) and Damien Chouly (77th min) both crossing to help reduce the eventual deficit. It wasn't, however, enough to even earn a defensive bonus for Jacques Brunel's team.

French champions Clermont Auvergne ensured they got off to a winning start with a confident 23-10 home victory against Saracens in Pool 2.

The home side were 12-3 up at half-time despite having two men sin-binned in the opening period as tries from Jamie Cudmore and Julien Malzieu put them in charge. Feisty Canadian lock Cudmore went on to be one of those handed a yellow, with Georgian prop Davit Zirakashvili also joining him in the ref's book.

Saracens gave themselves hope with David Strettle's 43rd-minute try early in the second half, but prolific Fijian Napolioni Nalaga wrapped up Clermont's win with his side's final try two minutes from the end.  

Unfancied Castres emerged with a highly creditable defensive bonus from their Pool 1 match at Northampton Saints, but the Top 14 outfit will rue a string of missed kicks as they narrowly failed to secure a priceless away win.

Full-back Pierre Bernard was wayward with three penalties and a conversion attempt as Castres lost 14-18 at Franklin's Gardens.