Kevin Hall, who pitched Oxon Hill to its first state semifianl victory in the last three years earlier this week, swatted a grand-slam home run in the sixth inning yesterday to give the Clippers a 5-2 come-from-behind victory over Southern of Harwood in the Maryland State Class A baseball final at Prince George's Community College.

"I was just waiting for the fast ball," said Hall, a junior All-Metropolitan selection who earned a 5-1 decision over Magruder Wednesday and was credited with a save in yesterday's triumph.

"Their pitcher, (Dale) Castro, has us fooled for a while, but we knew we'd get to him sooner or later."

As the Clippers posed for post game photographs, singing an off-key version of their theme song - "Proud Mary" - Oxon Hill coach Don Keyes picked up the championship trophy.

"I've been looking for this thing for a long time," Keyes said. "Thes guys have come so close for so long. They hung in there and really deserve it."

Castro, who had stifled Oxon Hill for the first three innings on no hits and seven strikeouts, helped his cause in the bottom of the third.

The winning pitcher in Southern's last four games, Castro one-hopped a drive over the 350-foot sign in center for a ground-rule double, moving John Noone to third.

The next pitch by Oxon Hill starter Byron New broke low into the dirt and Noone coasted in on the wild pitche for a 1-0 Southern lead.

Castro was brilliant in the fourth and fifth innings halting his opponents with a deceptive curve, retiring six straight and raising his strikeout total to 10.

Then, in the bottom of the fifth, freshman Carl Johnson increased the margin to 2-0, lofting the first pitch over the fence in left center.

It was only the fourth hit off New, who struck out the side.

But the signs of fatigue began to show on Southern's workhorse. McKinley Guess opened the Oxon Hill sixth with a rifle shot to right center for a double the Clippers' first hit. Jack McClanahan worked the count to 3-2 andthen drew a walk.

After Mike Matthews' attempted sacrifice failed, forcing Guess at third Mike Lady pushed a single to shallow center to load the bases for Hall.

The junior slugger crashed the first pitche deep to left. The ball sailed high over the fence as Hall pranced around the bases with castro, hands on hips, looking on in disbelief.

Danny Rice followed with a double down the third base line and scored on a throwing error by the second baseman on New's grounder.

Moments later, New was picked off first and was ejected for throwing his batting helmet.

When Oxon Hill took the field in the bottom of the sixth, Hall took over the pitching chores. He threw just 10 pitches to retire the side in order, and after hitting the first two batters he faced in the seventh, Hall sent the next three down to end the game.