Grosjean continued France's good start

But he raised his game in the third set, earned a string of break points and eventually broke Grosjean to take a 5-4 lead.

The set went to a tiebreak and Blake saved three match points before winning it 9-7 on his second set point.

He then roared to a 4-1 lead in the fourth only for Grosjean to battle back as both men slugged it out with breathtaking tennis.

Grosjean eventually won on his fourth match point after three hours and three minutes.

Earlier, Clement ripped up the form book to beat Roddick, who had won all seven of his previous Davis Cup matches.

"In the end I think I was more aggressive. You have to want it. I hung in there, even after missing a host of break chances," said a delighted Clement.

Roddick served 20 aces in the match but contributed to his downfall with 47 unforced errors.

The 20-year-old American had raced into a 4-0 lead inside a dozen minutes.

Missed chances

And the world number nine wrapped up the first set despite losing his serve to Clement in the eighth game.

Clement came back strongly in the second set and won the tie-breaker when his attempted drop shot just spun over the net.

In the third, Roddick missed break chances in the third and ninth games, then missed a set point in the 10th game.

Critically, he missed four more in the 12th game and Clement taking the ensuing tie break on his first set point as Roddick hit a forehand wide.

In the fourth, Roddick faded alarmingly and Clement could afford to waste break points as he managed to convert just two out of 15 to move into a 3-1 lead.

The Frenchman broke again for 5-1 and won on his third match point when Roddick netted a backhand.