The Vancouver Whitecaps edged the Washington Diplomats, 2-1, in a tie-breaking overtime shutout last night at RFK Stadium.

The disappointing loss was the Diplomats' sixth straight. Washington is 818. Vancouver snapped a two-game losing streak and is now 11-15.

The score was tied, 1-1, in regulation and neither team was able to score in overtime.

In a shootout, each team has five players alternate kicks on goal.

Bob Lenarduzzi and Steve Kember connected for Vancouver while Tommy O'Hara was the only Washington player to score against Whitecap goalie Phil Parkes.

The Whitecaps, possibly a bit tired after consecutive losses on the road to the Cosmos (3-2) and New England (2-0), appeared to be struggling in the first half.

The offense took too long to set up and consequently got off very few attempts on goal (five). A patchwork Washington defense did a fine job in containing the front three of Vancouver ad goalie Bill Irwin was forced to make only tough saves.

Vancouver was handicapped some since its top scorer, Kevin Hector, who has none goals this season, was sidelined with an injury. Striker Derek Possee came the closest to denting the Washington defense when his header, following a free kick by Alan Hinton, was slapped away by Irwin midway through the first half.

Possee got another uncontested shot but Irwin dove and smothered the ball.

Otherwise, Washington had things its own way.

The conservative Whitecaps played into Washington hands. The visitors were content to keep the ball in the midfield rather than attack, and that suited the win-hungry Dips fine.

With five straight losses hanging over their heads and only five goals in the process, Washington's offense was extremely aggressive.

Paul Cannell, Ray Graydon, Bobby Stokes and Mike Bakic got the ball often enough from midfielders Sakib Viteskic and newly acquired Dutch star Cus Hiddink forseveral good shots but were unable to connect in the early going.

Cannell, who has no equal in intimidating goalkeepers, was responsible for Washington finally breaking a scoreless tie to go ahead, 1-0, although the striker did not receive any credit for it. And Cannell shouldn't want any.

Tommy O'Hara sent a crossing pass from the left side in the middle for Cannell who leaped with Vancouver goalie Phil Parkes. Just as the Whitecaps' net man punched the ball out, Cannell yanked him to the ground. No foul was called as Parkes lay stretched out in the middle of the goal area.

Several players froze momentarily but Bakic rushed in and slammed the ball into the open net from 15 yards out to put Washington ahead at 10:58.

With their first goal in two games safely behind them, the Dips became even more aggressive. Cannell just missed a shot header moments later and Bakic sent two hard shots that Parkes stopped just short of the net.

Vancouver came out of the attack in the second half. But Irwin and Co. were not about to give anything cheap. Eight and sometimes help out on defense each time the nine jerseys dropped back to Whitecaps came looking for the tying goal.

That search ended when John Craven headed in a direct kick from Alan Hinton from eight yards out at 70:55.

Hinton floater seemed to catch Washington's pesky defense asleep and Craven was all alone to head the ball into the lower right corner past a driving Irwin.