With the exception of the opening kickoff, Seneca Valley's defense was flawless last night as the fifth-ranked Screaming Eagles pulled away in the second half for a 21-7 victory over Gaithersburg in a Montgomery AA game.

Visiting Seneca Valley raised its record to 7-0 and Gaithersburg, the defending Class AA state champions, fell to 4-3.

Quarterback Matt Kastantin and running backs Ricky Davis and Twain Parker each scored on short runs before 3,500 fans. The Trojans got their only points when senior Jamie Jefferson returned the opening kickoff 98 yards for a touchdown.

With the game tied 7-7 at halftime, the Screaming Eagles controlled the second half, holding the Trojans to minus-five total yards. Gaithersburg had 83 yards for the game.

"We knew we hadn't played to our potential in the first half and we knew we could control their lines in the second half," said Kastantin, who completed nine of 16 passes for 122 yards.

The Screaming Eagles went ahead for good on their first possession of the third quarter. Parker capped the 12-play, 80-yard drive with a one-yard run over the right side. John Duke's kick made it 14-7.

Senior John Joppy carried four times for 29 yards on the drive. Kastantin connected with Davis on a 36-yard pass to move the ball to Gaithersburg's 18.

Gaithersburg never entered Eagles' territory in the second half as end Shane Henson led a stingy defense.

Seneca Valley sealed it with 1:30 remaining when Davis ran around right end from one-yard out. Davis had 40 yards on the drive and finished with 70 yards (66 in the second half) on 12 carries.

The Eagles had other scoring chances, but Kastantin was intercepted by Derrick Wilson at the Trojans 10 and Duke missed wide on a 26-yard field goal attempt.

On Jefferson's return, he took the ball at the his 2, ran down the right sideline and then cut across field at the 50. He went untouched into the end zone.

"I picked up my blockers and I followed Van Chatman," Jefferson said. "When I got near midfield, I cut back in and I beat their last man, who was the kicker."

Seneca Valley tied it early in the second quarter when Kastantin rolled left and went into the end zone from three yards. It was a 15-play, 77-yard drive, consuming more than nine minutes.

Kastantin completed five of six passes for 58 yards on the drive.

Gaithersburg quarterback Jason Crawford completed only four of 11 passes for 26 yards. Chatman ran 10 times for 51 yards, but gained only one yard in the second half.

The Screaming Eagles had 279 total yards, 167 in the second half. Seneca Valley (7-0) 0 7 7 7 21 Gaithersburg (4-3) 7 0 0 0 7

G -- Jefferson 98 kickoff return (Venz kick)

SV -- Kastantin 3 run (Duke kick)

SV -- Parker 1 run (Duke kick)

SV -- Davis 2 run (Duke kick).