What in the world is Steve Stone going to do for an encore? The veteran Oriole righthander ended the first half of Baltimore's season tonight by winning his 11th consecutive decision.

In prevailing, 3-1, over the Kansas City Royals, Stone gave up only three hits in seven innings to run his record to 13-3, tied with Tommy John of the Yankees who has an identical record, for best in the American League. oAnd 41,514 tankard night fans saw him do it in Memorial Stadium.

The third largest home crowd of the season gave Stone a prolonged standing ovation before the game as he warmed up in the Oriole bullpen. The partisans were showing Stone their appreciation for his record-tying pitching performance in the All-Star Game when he retired all nine men he faced. Stone has not lost since May 5 (against Minnesota) and is 17-2 at Memorial Stadium since joining the Birds early last season.

Stone received relief from Tippy Martinez and Tim Stoddard over the final two innings to win his 13th game. It is only the second time in a nine-year career that he has won that many in a season. He was selected "player of the week" in the American League once and was June's AL pitcher of the month. With the first half of the season ending tonight (81 of 162 games) Stone could be in line for a Cy Young Award.

"No one on this club is thinking about personal goals or statistics," Stone said. "We're nine games behind the Yankees and if you look around this clubhouse you'll know that every player on this club is thinking about catching New York in the second half of the season. But we have to play our best against clubs like the Royals to do it."

John Lowenstein gave Stone an early 1-0 lead over the West Division leaders with his first home run of the season against Kansas City starter and loser Renie Martin (8-6).

The Orioles increased their lead to 3-0 in the sixth on Eddie Murray's two-run double to left-center field. His hit scored Bumbry, who had doubled when Willie Wilson lost his line drive in the lights, and Rich Dauer, who had walked.

During this time, Stone permitted Kansas City only two hits -- both opposite-field signles. He flirted with danger in the sixth inning when, after retiring the first two Royals, he walked the bases loaded.

Baltimore Manager Earl Weaver came out to talk to his ace but left him in to retire Amos Otis on a fly to Lowenstein. Stone, who struck out six and walked six, had more control problems in the seventh when the Royals got their run.

He walked Clint Hurdle, then retired Frank White and U. L. Washington before designated hitter Hal McRae doubled deep to right center to score Hurdle. Stone finished the seventh but did not come out for the eighth. Stoddard picked up his 12th save, and his seventh in relief of Stone.

"Tim did it again," Stone declared. "Once again the club picked me up. Stoddard has done an excellent job this year -- always coming in the game with men on base. And he always does the job."

Stoddard came on in relief of Martinez who walked a man and gave up a single before Stoddard retired Wilson and McRae on infield outs.

"I was never worried," said Stone.

He was a little worried in the fifth when he hurt his back on a pitch to the Royals' White. "Every now and then something goes out of whack back there," Stone said. "I was just trying to hang in there in the sixth and seventh, but my back is all right. Nothing wrong with it."

Meanwhile, in the Royals' clubhouse, several players were sitting around mumbling to each other about Stone's performance and how good his curve ball was.