Victory had looked a near certainty as Stade led by 10 with 68 minutes gone at the Stade Oceane but Grenoble fought back to level affairs as a converted Matthieu Nicolas try and a 74th-minute penalty from Clermont Darbo threatened to shock the twice beaten Heineken Cup finalists.

But just as both sides looked like they would have to settle for a draw following convincing successes in Round 1, Contepomi kept his cool to slot the winning kick and send Stade to the top of Pool 5.

The Parisian giants had earlier enjoyed the perfect start as Remy Bonfils crossed for the game's opening try with just three minutes on the clock.

Julien Dupy's conversion and a first penalty handed the hosts a 10-point lead after only six minutes and it was a case of a battle of the boots for the rest of the first half and much of the second.

A Nicolas Bezy drop goal and two more penalties from Dupy kept the scoreboard ticking over for Stade before the break but a hat-trick of three pointers from Nicolas Laharrague ensured Grenoble remained very much in the contest.

It was a case of more of the same after the restart as a Jules Plisson drop goal was sandwiched between two further Laharrague penalties in the first 15 minutes.

Contepomi's first penalty with 12 minutes left looked to have made the game safe for Stade as they opened up a two-score gap at 25-15 but the veteran midfielder would be called upon to win it all over again as the real drama unfolded late on.