J.P. Leigh, trailing by four after 11 holes of his semifinal match in the Virginia State Amateur golf tournament yesterday, did what any former professional would do.

He kept his cool.

The 37-year-old from Portsmouth closed the gap on the last seven holes, then won the first sudden-death playoff hole to defeat Miller Baber of Roanoke and reach the final of the tournament at the Country Club of Fairfax for the first time.

The win gives Leigh, who was the medalist, an opportunity to dethrone defending champion Tom McKnight of Galax in the 36-hole championship round beginning today at 8 a.m.. McKnight advanced by beating Billy Jahn of Norfolk, 2 up, and Chuck Wemp of Lynchburg, 4 and 3.

Baber reached the semifinals by beating another former pro golfer, Mike Pratt of Richmond, 1 up, and Wemp made it by stopping Sam Stein of Richmond, 2 and 1.

Leigh, who played on the PGA Tour in 1972 before regaining his amateur status, defeated Moss Beecroft of Newport News, 3 and 2, earlier yesterday in the quarterfinals. But he struggled on the front nine against Baber, a 20-year-old who attends Virginia Tech.

Leigh bogeyed Nos. 3, 5 and 6 and Baber birdied No. 4 to go 4 up after eight holes. Leigh birdied nine to close the gap, but Baber regained his edge when Leigh bogeyed the 11th.

Birdies for wins by Leigh on the 12th and 13th put pressure back on Baber, who began to struggle off the tee and could not find any putting rhythm. Baber's bogey at 15 cut his lead to one and another bogey at 18 gave Leigh the tie.

On the playoff hole, Baber's tee shot glanced off a tree and barely cleared a pond. He reached the green in four, but Leigh parred for the victory.

"I used a one-iron off the tee and I hit the top of (the ball)," Baber said of his drive at the 19th. "(The loss) will wear off in a couple of days.

"I was much happier with this round than some of my other ones, but I only played average on the back nine and (Leigh) played good.

"He played steady. He just kept trying and I kept trying. I just couldn't get the ball in the hole. On 18, I thought I hit a good second shot and I miscalculated. Then, I thought I hit a good putt and I missed again. I let him back in."

McKnight handily dispatched Wemp in his semifinal round, gaining control at the fourth hole when Wemp bogeyed. On the 15th, McKnight sank a 10-foot birdie putt to decide the match.