Tennis: Sampras' aces trump Ivanisevic: The Wimbledon men's champion serves notice of intent as a teenager makes a significant breakthrough in the women's game

THERE was bound to be the familiar shooting match when Pete Sampras met Goran Ivanisevic in the ATP Tour Championship here last night: less round-robin than shattered clay pigeon. Sampras delivered the big shots when it mattered to win, 6-3, 4-6, 6-2, eclipsing Ivanisevic's Tour ace record in the process.

Sampras's 15 aces took his total to 972, which is 15 more than Ivanisevic accumulated on the ATP circuit last year; though an asterisk is appropriate to point out that the Croat left-hander helped himself to a total of 1,066 free points last year, taking into account his Davis Cup, Olympic Games and Grand Slam Cup matches.

Moreover, some of the shots that hurt Sampras most last year boomed from Ivanisevic's racket during the Wimbledon semi-finals, delaying the American's coronation at the All England Club for 12 months.

While Sampras has established himself as the world No. 1, Ivanisevic has struggled to build confidence since injury hampered his progress early in the year; the irony being that Sampras's recent results guaranteed him a place as the last of the eight qualifiers for the Tour finale.

Until last night, Sampras had won only one of their six previous matches, his most recent defeat, in straight sets, coming in Paris early this month, and the second set provided ample evidence why. After a blistering start, in which he conceded only four points in winning the opening set in 26 minutes, the American offered his opponent an unexpected reprieve.

Sampras, who had three break points at 3-3 in the second set, seemed dismayed when Ivanisevic suddenly found the rhythm to serve his way out of trouble. Three games later, when the Croat had his first break points of the match, Sampras double-faulted to present him with the set.

By his own admission, Sampras has tended to lose heart in the past when Ivanisevic has been able assert himself. On this occasion he did not waver. Though Ivanisevic saved two break points in the opening game of the final set, Sampras cracked his serve in the fifth game and again in the seventh. The Croat had become tentative, particularly on the backhand, which cost him dearly whenever rallies were allowed to decorate the scene.

'I played too safe,' Ivanisevic lamented, 'and I served really badly. He was guessing where I would put the ball before I hit it.' Though 10 aces took his haul for the year to 757, he was grounded by a low percentage of first serves and 29 unforced errors.

Sampras, who won the title in 1991, not only served with his customary power, but varied the pace and placement of his deliveries to add to the confusion of his opponent. 'I don't want to be too predicable,' he said.

The evening's second round robin, between Michael Stich and Michael Chang provided a spectacular contrast, the players scurrying about the court, either making winners or retrieving them. Stich moved closer to a place in Saturday's semi-finals with a 4-6, 7-6, 6-2 victory to add to Tuesday's straight sets win over Andrei Medvedev.