Pierce’s Planned Semifinal Match Runs Into a Snag : Tennis: Instead it will be Jana Novotna, a 6-4, 6-0 winner, who plays Steffi Graf in the semifinals.

NEW YORK — Seventh-seeded Jana Novotna defeated No. 4 Mary Pierce 6-4, 6-0 today to join top-seeded Steffi Graf in the semifinals of the U.S. Open.

Pierce, who upset Graf to reach the final of the French Open earlier this year, couldn’t control her own power game, repeatedly hitting long.

“I’m very disappointed because I was looking forward to playing Steffi again,” said Pierce, who has lost to Novotna both times they have met.

Instead, it is Novotna who will play Graf, a 6-0, 6-2 winner over Amanda Coetzer in the day’s first match.

Neither Novotna nor Pierce took command in the opening set, which featured five service breaks while the two held only four times.

“She was hitting quite well in the beginning of the match,” Novotna said of Pierce, “but it didn’t work so she changed her game.”

For Pierce, it was a change for the worst as Novotna, growing more and more confident, ripped through the final six games.

“I was very confident that I had the game to beat her,” Novotna said. “I didn’t really serve and volley all the time. I just mixed up my game, was very aggressive all the time.”

Novotna, who has never made it past the U.S. Open fourth round until this year, moved Pierce from side to side and from the baseline to the net, waiting for her opponent to make a mistake. And she did as Pierce committed 37 unforced errors, 15 more than Novotna.

“She never game me any free points and I made too many mistakes,” Pierce said.

Novotna replied: “Today it was fun.”

Graf, seeking her second consecutive and fourth overall title at the National Tennis Center, took only 55 minutes to eliminate her 11th-seeded South African foe.

“Time is something I don’t really care too much about,” said Graf, who hasn’t been kept on court more than 55 minutes by any of her four victims so far.

In men’s quarterfinal matches, No. 9 Todd Martin took on Germany’s Bernd Karbacher, while crowd-favorite Andre Agassi was playing No. 13 Thomas Muster of Austria in night matches.

Eight minutes into the day’s first match, Graf has as many games as Coetzer did points, building a 3-0 lead. In the next game, Coetzer reached game point for the first time. It, along with the game, were quickly victims of Graf’s relentless power game.

Graf lost her perfection eight games into the match when Coetzer held at 30, earning an ovation from the crowd in Louis Armstrong Stadium. Four games later, she lost a 40-0 lead before finally holding serve again.

Then came the seventh game when Coetzer threatened to break Graf’s serve, twice reaching ad point.

It was just a speed bump in Graf’s road to the semis as she held with a forehand passing shot, then broke Coetzer at 15 to close out the victory.