If a modern Rodin were chiseling The Forehand, he'd use Ivan Lendl as his model, capturing the Czech in midstride as he flies along the base line, getting set to turn a yellow tennis ball into a golden blur with a flick of his wrist.

Today, in the final of the Grand Prix Masters, an interloper named Vitas Gerulaitis tried to chip that statue into a heap of rubble. And he almost succeeded, before losing the $100,000 prize in five sets, 6-7 (7-5), 2-6, 7-6 (8-6), 6-2, 6-4, before 17,652 delighted patrons in Madison Square Garden.

Art loves symmetry and, as Gerulaitis has noted, Lendl is all lopsided. For 2 1/2 hours, Gerulaitis cruelly critiqued Lendl's flaw: his backhand.

In particular, Gerulaitis exposed Lendl's inability to dig out soft, undercut slices below knee level in the backhand corner. Chip, chip, chipping at that weakness, Gerulaitis brought the second-ranked player in the world to the brink of a straight-set upset.

Then, at the last possible instant--down by two sets to none and facing match point in a tie breaker--Lendl showed that he was a man, not a statue.

Battling back with heart and an unexpected gift for tactical improvisation, Lendl survived a test of 3 hours 50 minutes and extended his victory streak to 36 matches and seven tournaments. The last fellow to beat Lendl was Gerulaitis, in five sets in the quarterfinals of the U.S. Open.

Although Lendl has won $1.3 million the past two years, this was, as he said, "my first big title." This long afternoon Lendl began laying to rest the notion that, despite his model exterior, he might lack something on the inside.

"I told myself, 'Keep fighting, fighting, fighting,' " said Lendl.

Little was expected of this match between the tournament's last seed and its top seed. It proved to be a delight.

Perhaps the most fascinating aspect of tennis is the interplay between contrasting styles of play: this match was a laboratory case in point.

"There's only one way to play this guy," said Gerulaitis, who only got into this hoity-toity eight-man field because Bjorn Borg withdrew. "He's got a lousy backhand . . . compared to his forehand. You just have to keep chipping it back there and make him stay in one place. Then, there's really not much he can do to hurt you.

"But if you make the mistake of going corner to corner with him, like (John) McEnroe tried to do (in Saturday's semifinals), he'll run you ragged."

Since Gerulaitis has had far more success against Lendl in recent months than anybody else, it's safe to say that slices to Lendl's backhand will become a constant diet.

Lendl's improvisational answer to Gerulaitis' tactical challenge was daringly unconventional for a textbook-perfect, often mechanical player. Lendl chose the same homely solution of desperation that most public parks amateurs would. For the last three sets, Lendl comically "ran around" his backhand just like a weekend hacker, even when it took him entirely off the court.

Gotta do what ya gotta do. But for Lendl, who wants to be No. 1 on the planet, it's not what you'd call a resolution of the difficulty.

"Vitas started to get tired," said Lendl, who has informed people here he prefers his first name be pronounced E-VAHN. "His slices to my backhand did not have as much depth or speed. It became easier to wind up for the forehand."

Lendl, the 21-year-old son of an Ostrava lawyer, is, like Martina Navratilova and Hana Mandlikova, a product of Czechoslovakia's tennis development program. His game looks like it came out of a marriage between a computer and Borg. A decade ago, Borg showed the virtues of top spin from both wings, an unflappable and bland disposition, plus unerring consistency on passing shots. Five years later, guess what? The Czechs had cloned the West's best product: his name was Lendl. Except that Lendl was, at 6-foot-2, four inches taller than Borg and had a hard serve.

Despite his test-tube tennis virtues, his excellent court manners, his occasional shy smiles and his facility in six languages, Lendl still had to prove several things to the tennis community. After failures at Wimbledon and the U.S. Open, could he win a major event? Was he just a tennis cash register, playing in more events than any other top pro, but winning mostly in events like the Bangor Open? Could he think in the heat of battle?

In the third set of this match, Lendl gave a lot of answers.

Starting with the last four points of the first-set tie breaker when Gerulaitis, down 5-3, pulled out the set thanks to three errors by his opponent, everything went against Lendl. He lost nine of 11 games as Gerulaitis chipped repeatedly to the backhand, then picked his spot to come to the net and punch away one solid volley after another.

Lendl's nadir, and the turning point of this match, came when Gerulaitis had three break points in the third game of the third set that would have put him ahead by two sets and two breaks. "If he had won that game to go ahead, 3-0," said Lendl, "I knew that, somehow, he would manage to serve out the match. I could not lose that game."

So, running around his backhand wildly, Lendl gambled on opening angles and getting Gerulaitis in a corner-to-corner game. It worked.

On the point that fended off the final break point, Gerulaitis was trapped at the net as Lendl unloaded a loud forehand on a lame volley. The ball smacked Gerulaitis directly in the forehead and knocked him head over heels.

Having escaped, Lendl began his comeback.

One more great escape was necessary. With Gerulaitis ahead, 6-5, in the third-set tie breaker, Lendl--2 hours and 34 minutes into the match--was down to his second serve on match point.

"I thought he would return and come to the net and make me pass him," said Lendl, "so I gambled and put a little extra on the serve."

Gerulaitis has always had a knack for getting to the brink of greatness, then failing. Once again, just as on a vital break point against Borg in the fifth set at Wimbledon in the '77 semifinals, Gerulaitis could not bring himself to the net against that second serve.

"I should have come in . . . big mistake," said Gerulaitis, who has won two Italian Opens and a WCT championship, but never a title that would have matched a victory today. "If the guy can pass you on break point, he deserves to win."

But Gerulaitis stayed planted and ended up hitting a backhand wide.

That was the end. Lendl won the next three points and the set. The last two sets seemed, in retrospect, a formality. Gerulaitis had missed his moment, again.

Standing at midcourt, holding his trophy, Lendl told the crowd, "Even though you are cheering against me when I play (New Yorkers) McEnroe and Gerulaitis, you don't know how much I like you and how very happy I am to have won my first big title in New York."

As Lendl finally smiled, the crowd, so cool toward him all week, cheered loudly.

They seemed to sense that today the statue had a human heart.