Lower Merion

advanced to the first round of the state team tennis tournament with some impressive momentum yesterday.

The unbeaten Aces (19-0) not only won the District 1 Class AAA team championship; they dominated in a 5-0 victory over visiting Council Rock South.

With the win, the Aces earn an advantageous site (Perkiomen Valley) in next week's state tournament first round against District 3 representative Manheim Central.

District 12 Class AAA. At 33d and Dauphin, Central coasted to a 4-1 victory over Northeast to win that championship.

The Lancers can win two championships in as many days this afternoon when they use the new outdoor courts at the Arthur Ashe Tennis Center to try to earn another Public League title against Masterman.

Except for Daniil Mamalat's win at first singles, the Lancers got straight-set wins in every match, including second and third singles from Robert Troyer and Gabe Steerman.

It was the first championship at Central as head coach for first-year mentor Michael Horwits, who is a 1992 graduate of the school.

District 12 Class AA. At Haines and Ardleigh, Masterman earned the title with a 4-1 win over Engineering and Science. The Blue Dragons (9-1), whose only loss was to Central, dropped only the first doubles match. They got singles wins from Kenny Greene, Max Weiss and Rueben Hampton.

Catholic. Mike Oliver survived a tough first singles match against Lou Vessels, leading La Salle to a 54-34 win over Roman Catholic in one league semifinal.

The perennial powerhouse Explorers will try to knock off two-time defending champion St. Joseph's Prep today at La Salle University (3:30 p.m.) for the league title.

The Hawks beat Archbishop Ryan, 62-32, in the other semifinal.

Baseball

Freshman Mike Raimo two-out triple in the fourth inning helped host

Strath Haven

rally from a four-run deficit and beat

Upper Darby

, 11-8, in a Central League game.

Raimo's triple with the bases loaded produced the game's fifth, sixth and seventh runs to turn a 7-3 deficit into a 7-7 tie. Batting in the No. 2 spot, Raimo had two hits and five RBIs on the day and scored to put the Panthers ahead for good, 8-7.

First baseman Ryan Krauss drove in four runs and leadoff hitter Taylor Smith contributed two hits for Radnor in its 6-3 win at Ridley.

Conestoga pounded host Penncrest, 13-3, as Sean Behm went 2 for 3 with three RBIs and Steve Hickey went 2 for 3 with four RBIs in the five-inning game.

Suburban One American. Andy Noga pitched a one-hitter for host Cheltenham in a 4-1 win over Wissahickon. Teammate Bryan Wilde was 3 for 3.

Public. Jorge Santiago's three hits helped Mastbaum win at Kensington, 14-4.

Brian Susten's grand slam in the sixth inning gave Northeast a 7-6 win at Edison.

Daniel Rodriguez and Jeffrey Bru combined on a four-inning no-hitter as host Frankford pummeled Lincoln, 15-0.

Ben Cruz got on via a bunt single, stole second and third and scored on a sacrifice fly by Deivis Santana in the bottom of the seventh inning and give Olney a 10-9 win over visiting Prep Charter.

Kevin Rycek hit a pair of doubles to power Franklin Towne Charter's win at Philadelphia Electrical, 13-9.

Mike Braun pitched a one-hitter for Central in its 16-0, four-inning win at Saul. The lone hit came early, the first pitch of the game, a John Demalavez single. It was his second win of the season in as many starts, the first by a 14-2 score against the same Razorbacks team earlier this season.

Penn-Jersey. Brandon Breslow went 3 for 3 with nine RBIs and Isaac Steinberg pitched a no-hitter as Akiba Hebrew pounded host International Christian, 24-0.

Track and Field

Roy-Al Edwards' anchor of the 4x100-meter race gave

Strath Haven

a slim win over

Upper Darby

to highlight the Central League Championships at Lower Merion.

The Strath Haven team of Eric Frasier, John DiCarlo, Willie Curry and Edwards posted a 43.2 to nip the Royals by one-tenth of a second.