Four urban high schools enjoyed a day in the country yesterday. The innercity representatives feasted on Northern Virginia competition, sweeping four games by a total of 101 points in the opening round of the Edison Holiday Invitational Tournament at Edison.

Eastern dropped Oakton, 85-64; McKinley disposed of Robinson, 77-55; Cardozo defeated Edison, 55-41; and Dunbar of Baltimore demolished Falls Church, 93-49.

Cardozo will meet Dunbar at 5 p.m. and Eastern will face McKinley at 9 in today's semifinals. Edison plays Falls Church at 2 and Robinson challenges Oakton at 7 in the losers' bracket.

"I would have to say that the city schools would have to have much greater overall talent. Yes, I would have to say that," said Cardozo Coach John Nunn. "But, this is a nice tournament out here. I'm glad we were invited."

Nunn's Clerks (3-1) received the stiffest challenge of the day from the hosts, needing to hold Edison (0-8) scoreless for the final 5:56 of its contest. The Clerks scored the final 14 points of the game, including six points by Raymond Hunt and four by Michael Wright, the day's high scorer with 27 points, to break a 41-all deadlock.

Harry McFadden's 18-foot jumper from the left corner with 4:20 left put the Clerks ahead to stay, 43-41, after six consecutive Eagle points, five by Darrick Simms, tied the score at 41 and negated the largest lead for either team.

Dunbar (8-1) held Falls Church (1-5) scoreless in the first quarter. A ball-hawking 3-2 zone defense allowed the Jaguars only three shots and forced nine turnovers. The Poets led 16-0 before Mike Angelini's layup put Falls Church on the board 39 seconds into the second quarter.

Leading the Poets were superquick guards 5-foot-11 Kevin Bush, who had 14 points, and 5-8 Dwayne Wood, who had six steals and made several assists on passes that defied logic.

Eastern (4-0), which jumped to 8-0 lead in the game's first 90 seconds on layups by John Chesley and George Robb, never saw the Cougars pull closer than six points.

Still the Ramblers did not put Oakton (3-4) away until late in the third quarter when they scored 14 unanswered points, fueled by five Cougar turnovers, to take a 69-47 lead with 6:24 left.

Chesley, a 6-5, 220-pound power-forward, was virtually unstoppable. But after the Ramblers jumped to a 16-3 lead, they seemed to lose interest in working the ball inside. The Ramblers also abandoned their pressing 3-2 defense which forced six quick Oakton turnovers for a sloppy, hacking man-to-man.

Oakton pulled within seven points midway through the third quarter and the Cougars might have come closer, but made only 10 of 24 shots from the foul line.

McKinley (5-1) trailed for most of the first half as the disciplined Robinson squad refused to allow the Trainers to exploit their massive height advantage. But with 3:34 left before intermission, the Ram shots stopped falling and McKinley scored the last 10 points to take a 31-25 locker room advantage.

Martin scored 10 of his points in the third quarter, including eight straight midway through the thrid period as Tech rolled to a 47-32 lead over the Rams (1-6) before the end of the quarter.