Mark Jansen of Robinson High School won the last two holes of the match to edge Wally Coulther of McNamara, 1 up, and win the championship of the 54th Frank Emmet Schoolboy golf tournament yesterday at the Country Club of Fairfax.

For Jansen, the win was his second come-from-behind victory in as many days. In a Thursday semifinal against Hunter Albright, Jansen won the 18th hole to force extra play. He went on to win on the 21st hole.

Yesterday, Coulther needed a 20-foot birdie putt at the 15th hole to take a commanding, 3-up lead.

Instead, he hit his birdie putt attempt six feet past the hole, missed coming back and lost the hole, allowing Jansen to close within one.

On No. 17, Jansen sank a 60-foot birdie putt to tie the match. Jansen would probably have won the hole with par or even bogey, as Coulther found heavy rough with his first two shots and faced a 15-foot putt for bogey. Jansen sank another cross-country putt, a 90-footer for par, to halve the 10th hole.

The two came to the decisive par-4 18th hole even, but both failed to reach the green with their second shots.

Coulther chipped his third shot 20 feet past the hole and Jansen chipped eight feet short. Coulther missed his putt and took bogey. Jansen, who made his share of clutch putts all week, then made the par putt for victory.

"I don't like close matches, but I'll take them if I win them," said Jansen, 17, bound for George Mason on a partial golf scholarship. Jansen credited his caddie, Chris Forbes, with helping him read the putts. Jansen said when he trailed late in the match, he and Forbes went into their "playoff mode" of concentrating more on every shot.

Coulther, 18, bound for Maryland's golf team, said the turning point was his missed birdie putt on the 15th hole. "I had been coming really close on my putts. On that one, I just hit it a little hard. As soon as I hit it, I knew it was going way by the hole."