Utility infielder U. L. Washington's single in the bottom of the 10th scored Clint Hurdle from second base with the winning run yesterday to give the Kansas City Royals a 6-5 victory over the Boston Red Sox.

Hurdle doubled to right field with two outs in the 10th off losing pitcher Dick Drago, after an intentional walk to Tom Poquette. Washington, who entered the game in the ninth after starting shortstop Fred Patek was removed for a pinch hitter, hit a ball to the fence to drive home Hurdle with the winning run.

Trailing, 5-3, the Royals tied the game in the eighth inning when Red Sox reliever Bill Campbell walked home two runs with the bases loaded.

Home runs by Fred Lynn, Dwight Evans and Jim Rice accounted for four of Boston's five runs. Rice's homer, which gave Boston a 5-3 lead in the seventh, was his 24th of the season but his first in 21 games.

Bombo Rivera, who had singled, with the Twins' fourth run in the bottom of the inning. Ford then followed with a single to center to give Minnesota the go-ahead run.

Dave Goltz (9-6), allowed 14 hits, including six in three-run Oriole third, but hung on to go the distance.

Baltimore starter Scott McGregor (10-9) suffered the loss, going the first 6 1/3 innings and giving up all five Minnesota runs.