FREDERICK, MD., AUG. 12 -- The Prince William Cannons batted around in a four-run eighth inning today and beat the Frederick Keys, 7-4, in front of 3,811.

Second-place Frederick fell 2 1/2 games behind the Northern Division leading Cannons.

Winner Ed Martel (7-9) lasted five innings, then Mike Gardella earned his 25th save this season.

The Cannons took the lead in the first inning with two runs on a walk to Dave Silvestri and singles by J.T. Snow and Sherman Obando, sandwiched around Enrique Hernandez's groundout.

In the Keys' fifth, Tyrone Kingwood's double provided two runs, both unearned because of second baseman Mauricio Zazueta's error.

The Cannons put the game out of reach in the eighth. After designated hitter Hernandez singled to left, Obando beat out a hit to short. Then Russ Davis hit a line drive over the left field wall for a 6-2 lead. Zazueta singled and stole on the next pitch. Then reliever Mike Deutsch walked a run home.

In the bottom of the inning, Ed Horowitz singled and scored when Melvin Wearing doubled. Wearing took an extra base when center fielder John Viera misplayed the ball. Tony Beasley's line single to left made it a 7-4 game.

P.WILLIAM ab r h bi FREDERICK ab r h bi Viera cf 3 1 2 0 Gilbert cf 3 1 1 0 Silvestri ss 2 1 0 1 Lewis dh 5 0 0 0 Snow 1b 5 1 2 1 Holland lf 5 1 1 0 Hernandez c 4 1 1 1 Kingwood rf 4 0 2 2 Obando lf 4 1 2 1 Rose 3b 4 0 1 0 Davis 3b 5 1 1 3 Horowitz c 2 1 1 0 Knoblaugh dh 4 0 1 0 Wearing 1b 3 1 1 0 Zazueta 2b 4 1 3 0 Beasley 2b 4 0 1 1 Howell rf 3 0 0 0 Berthel lf 1 0 0 0 Kessinger ss 3 0 0 0 Totals 34 7 12 7 Totals 34 4 8 3 Prince William 201 000 040 7 Frederick 000 020 020 4

E: Zazueta, Howell. DP: Prince William 1, Frederick 2. LOB: Prince William 8, Frederick 8. 2B: Wearing. HR: Davis. SB: Viera, Zazueta. S: Silvestri. CANNONS IP H R ER BB SO Martel (W,7-9) 5 5 2 0 3 1 Gilbert 2 0 0 0 2 1 Moody 1 3 2 1 0 1 Gardella (S,25) 1 0 0 0 0 0 KEYS IP H R ER BB SO Kerr (L,12-7) 6 8 4 4 3 2 Deutsch 1 1/3 4 3 3 2 0 Riddle 0 0 0 0 2 0 Mondile 1 2/3 0 0 0 0 0

T: 2:48. A: 3,811.