Jim Castagna birdied the final hole in the drizzle yesterday as he and Crofton clubmate Mike Toomey swept two matches and gained this morning's semifinals of the Belle Haven Four-Ball golf tournament.

Castagna and Toomey play Jack Skilling of Chevy Chase and Matt Sughrue of Bethesda in one semifinal at 8 a.m., while Rick Gould of Belle Haven and Dave Anthony of Lynchburg, Va., contest University of Maryland teammates Mike Richard and Steve Fellinger in the other at 8:10.The winners will play for the championship this afternoon.

In their morning match, Castagna and Toomey had built a four-hole lead after 11 holes on what Castagna called an "uncontrollable case of the drains." He "drained" three birdie putts and one-putted three other times on the front nine.

When Castagna three-putted from 12 feet to lose the 12th hole, their opponents, Virginia Amateur champ Neff McClary and Wilson Dickerson, seized the opportunity and went on to even the match after 18 holes. Castagna and Toomey won that morning match with par on the first extra hole.

In the afternoon, against Tim Vigotsky and Dick Hill, the Crofton pair again took an early lead that was squandered.

Hill canned a 20-foot birdie putt on the difficult ninth hole to complete a three-hole sweep and square the match at the turn.

After Castagna and Toomey won the 10th and 12th holes with pars, Hill, rock steady under pressure, sank a 40-foot birdie put to win the 15th.

Vigotsky sank a 15-footer for par to square the match on the par-three 17th.

On the final hole, Castagna was the only one of the foursome to hit the fairway with his tee shot. A wedge shot stopped five feet from the hole on the uphill, par-4. He sank the putt for birdie and victory.