Twenty-seven-year-old Martina Navratilova retained her U.S. Open women's singles title because, over three sets, Chris Evert Lloyd could not withstand the heavy pressure she applied.

Against all but Evert, Navratilova's left-handed serve and speed afoot earns her easy winners. Today, Navratilova faced a sharper, more versatile Evert, so she had to go the distance.

Seldom has the right-handed Evert been as forceful with backhand passing shots. Navratilova's bread-and-butter shot is her Continental-gripped, cross-court forehand hit with topspin. Evert anticipated the shot well this time and was able to hit the backhand cross court for winners.

Evert also mixed her passes with some of the best lobs seen here in years. Unfortunately, she does not have the option to serve and volley, so she seldom earns easy points when serving. Acutely aware of this, Navratilova was relentless in pressing the attack at the net.

In this age of big, underhand-gripped, topspin forehands, Evert still uses the classic Eastern grip, which places the hand directly behind, rather than slightly under, the racket handle. Consequently, she cannot hit a variety of spins. This leaves her particularly vulnerable to low balls. Navratilova's backhand approach is always hit with underspin.

When these two played the Wimbledon final two months ago, Evert took a quick 3-0 lead, only to fade because she could not sustain her base-line attack. Even after winning a set in this, their 61st meeting, few seriously thought she could win. Neither did I.

Navratilova had too much offense for Evert's patterned, predictable defense.

In the first men's semifinal, played before the women's final, Pat Cash forced Ivan Lendl to the limit before losing the fifth-set tie breaker, 7-4. Cash was serving at 6-5, 30-love, in the last set.

Lendl won because his passing shots -- his backhand, in particular -- found the mark. Cash's hyperagressive style took him to the net as often as possible and quick feet gave him the freedom to take chances.

I was convinced Cash was going to win at 5-5 in the fifth set after Lendl lost a match point in his favor at 4-5, 30-40. But he made errors at the net and Lendl kept his passing shots in the court. In the recent past, Lendl has chosen riskier passes. This time, he wisely opted to hit safely to allow his relatively inexperienced opponent a chance to make an error.

Although he won, Lendl's showing reinforced his refusal to round out his base-line game by approaching the net more often. At 6-2, he would be difficult to pass. He came through against Cash by a nose. The next time, he may not be so lucky.

Lendl's opponent for Sunday, John McEnroe, defeated Jimmy Connors, the winner here in 1982-83, for the eighth straight time, 6-4, 4-6, 7-5, 4-6, 6-3.

This was Connors' first Open with his new mid-sized racket. His serve and ground strokes now fly off the strings faster than before; with the ability to hit a two-fisted backhand at the last minute, he left McEnroe guessing at the net more than before. A radar gun has clocked Connors' backhand at more than 100 miles per hour.

By contrast, McEnroe relies more on pinpoint placement. His mid-sized racket is strung at a loose 48 pounds, thereby creating a tremendous trampoline effect. This gives McEnroe touch on his volleys and lobs. In the tense fifth set, it enabled him to swing fluidly. Connors tended to overhit.

McEnroe's new weapon may be his new, composed court demeanor. He actually smiled at times during the match, seemingly convinced that it was just a matter of time before he took control. Down a break in the third set, he remained calm and serene. Just months earlier, he would have been verging on a tantrum.

The critical difference in this meeting, as in previous matches, was McEnroe's all-court game.

In Sunday's final, McEnroe will face a more confident Lendl, who is seeking his first Open victory. The key for either may rest with Lendl's tendency to mis-hit his heavily topspin ground strokes at crucial times. My prediction: McEnroe in four sets. After all, he has never lost a final appearance here, having won in 1979-81.