A one-yard plunge by Montgomery-Rockville quarterback John Kaleo with 5:57 left ended a 70-yard drive and clinched a 26-22 upset victory over Nassau Community College yesterday at Montgomery Stadium.

Cornerback Carl Owens's recovery of Craig Mitter's fumble with 3:30 remaining quelled Nassau's last drive.

Nassau (2-1) entered the game ranked third by the National Junior College Association, Montgomery-Rockville 21st.

The victory was "the biggest in the school's history," said Knights Coach Phil Martin. "I can't get over this one. We beat what's considered the best team on the East Coast. That makes us the best in the East now."

The teams traded the lead four times in the first half, the Knights (3-0) holding a 20-13 advantage at intermission. Montgomery made its first statement a loud one, freshman running back Dwayne Freeman negotiating the left sideline for a 58-yard touchdown on his team's first offensive play.

But Nassau's Phil Lang threw to Jeffrey Blackmon for a 40-yard touchdown. Blackmon beat Mike Rucker and made a leaping catch in the end zone for the 7-6 lead.

Kaleo, who completed 10 consecutive passes at one point, found two ex-Good Counsel receivers to key the next scoring drive. After connecting with tight end Brett Reese for 27 yards, Kaleo found Carlos Smith for 10 yards, the first of Smith's two scores.

Kaleo, from Bowie High, completed 17 of 27 passes for 215 yards. He credited his offensive line: "They were outstanding. . . . This is a great feeling, I have no words for it."