Defending champion Robert Cheruiyot of Kenya won his fourth Boston Marathon on Monday, while Ethiopia's Dire Tune took the women's crown in the event's tightest finish.

Cheruiyot, the first Kenyan man to win four Boston Marathons after victories in 2003, 2006 and 2007, controlled the pace through the hilly Boston suburbs and was followed in second place by Abderrahime Bouramdane of Morocco.

It was the 16th time since 1991 that a Kenyan has won the world's oldest annually contested marathon.

The 29-year-old put distance between himself and a thinning pack of runners about one-and-a-half hours into the race but slowed in the final stretch to miss by 32 seconds his own 2006 course record.

"The course is so tough, so it feels great to me," he told a news conference after winning the US$150,000 winner's prize and becoming only the fourth man to win four Boston Marathons.

He also earned a likely chance to represent Kenya at the Beijing Olympics in August.

The real drama was in the women's field, where Tune and Russia's Alevtina Biktimirova battled shoulder-to-shoulder through the final stages with both runners sprinting ahead of the other as they neared the finish line.

"I am happy to be winning in Boston," said Tune, 22, who placed second in last year's Olympic Commemoration Marathon in Nagano, Japan, and is only the second Ethiopian to win since the women's competition began in 1972.

Biktimirova, 25, trailed by just two seconds, finishing in 2:25:27.

"I wanted to win very badly. I was fighting until the end," she said.

"In the end I just didn't have enough speed."

In the men's race, Cheruiyot finished the 112th edition of the Boston Marathon in an official time of two hours, seven minutes and 46 seconds, in ideal race conditions.

Born into poverty, the lanky Cheruiyot who once worked in a friend's barber shop to eke out a living is now one of the richest sportsmen in Kenya.

Bouramdane finished second in 2:09:04 and Khalid El Boumlili, also of Morocco, third in 2:10:35.

Only one American finished in the top 10, Nicholas Arciniaga taking 10th place. The last American to win the Boston Marathon was Greg Myer in 1983.

Tour de France winner Lance Armstrong finished his first Boston Marathon in 2 hours, 50 minutes, 58 seconds.

Boston was Armstrong's third marathon after running in the New York race twice.

(Agencies April 23, 2008)