The showdown between last season's winners and the champions of 2001 and 2002 delivered everything that was expected as Europe's premier club competition again set the season alight after a month of domestic mediocrity.

Ronan O'Gara was the Munster hero as he landed a 50-metre penalty in the last few minutes to claim the win after Leicester had briefly edged in front for the first time.

Munster began impressively and led 15-6 at the break after tries by Donnacha O'Callaghan and David Wallace.

Leicester improved after the break and the game was thrown wide open 10 minutes from time when the referee ran out of patience as Munster repeatedly hauled down a dominant Leicester scrum near their line and awarded a penalty try.

Andy Goode converted to take the hosts to within two points then landed a long-range penalty three minutes later to put them 19-18 ahead.

The Leicester fans were up to acclaim another famous comeback but their cheers died in their throats as O'Gara defied the mud and rain -- after escaping with an unseen knock-on -- to land his long-range shot in injury time.

"It was a great win, we showed good resolve and it was important that we got our season off to a good start," O'Gara told Sky Sports.

"We've been struggling in our domestic league but I think the Heineken Cup brings out the best of us," added the Ireland flyhalf.

O'Gara said he definitely knocked on "about four or five feet" before the tackle that earned the match-winning penalty and also apologised for any offence caused in the build-up to the match when he questioned the quality of English rugby.

Leicester coach Pat Howard rued two first-half missed try-scoring opportunities and said: "We are now in the same situation as Munster were a year ago when they lost their first game -- there's a long way to go."

Last year's runners-up Biarritz got off to a good start as four tries in the first 45 minutes earned them a bonus point in a 22-10 win over Northampton in Pool Six, which mean Wasps were the only one of the six English teams to claim a win on the opening weekend.

However, Wasps, champions in 2004 but outside the knockout stages in the last two seasons, only just scraped a 19-13 home success over Castres in Pool One.

The London club also lost back Josh Lewsey to a hamstring injury that could rule him out of England's opening November international against New Zealand in two weeks.

"It was ugly but we stuck in there," said Wasps coach Ian McGeechan, who must have feared a repeat of last year when his side lost their opening game to Edinburgh.

In Saturday's action there was an upset in Ireland where Ulster thrashed three-times champions Toulouse 30-3, with all the points coming in the first half.

It was a great weekend for Wales as the Neath-Swansea Ospreys beat Sale 17-16 when James Cook landed a last-kick conversion of an injury-time Shane Williams try, Llanelli Scarlets won 32-25 at London Irish and Cardiff won 13-5 at Bourgoin.

There were also opening wins for Leinster, Agen, Borders, Stade Francais and Perpignan.