Mary Pierce, runner-up at the French Open earlier this month, reached the quarter-finals of The Championships for only the second time in 10 attempts when she defeated Italy's Flavia Pennetta 6-3 6-1.

Pierce played with power and authority, particularly in the second set when her booming forehand found its range, to see off with comparative ease a dangerous opponent who had defeated her in their only previous meeting two years ago.

Pennetta, who has won two tournaments in Latin America on clay this year and was seeded 26th, had not dropped a set on her way to the fourth round. Relying entirely on a baseline game, she matched the big-hitting Pierce for power and accuracy for the first seven games. Then the 30-year-old Pierce, the 12th seed, responded to cries of "Allez Marie" from her French supporters by upping the pace and breaking Pennetta on her second break point. A great crosscourt backhand from Pierce conjured the break point and Pennetta dropped serve when she struck a backhand a foot too long.

Visibly lifted, Pierce served out the set to love in 32 minutes and kept the momentum going by breaking serve, again to love, at the start of the second set. As Pierce's groundstrokes settled into an impressive groove, Pennetta's serve buckled under the strain. Having played the opening set without a double-fault, she perpetrated five of them as the pressure increased.

The 23-year-old Italian's hopes of staying in the match crumbled when Pierce broke for a third time in the match to lead 4-1. Running Pennetta from side to side and hitting with pinpoint accuracy, she has rediscovered the form that brought her Grand Slam titles in 1995 (Australia) and 2000 (France).

There was, however, a "typical Mary" finish to the match when she needed five match points to seal the victory on Pennetta's serve. Pierce missed two of them on simple errors and the Italian saved the other two with brave winners. But when a simple put-away set up match point number five, Pierce struck perhaps the best shot of the 65-minute match, a running backhand from wide of the tramlines which arrowed into the deepest corner. It was an appropriately brilliant winner for a first-class performance.