The Orioles already had left eight men on base and were threatening to leave the bases loaded in the 10th when Joe Nolan hit a two-out, two-strike grand slam home run that gave Baltimore a 7-3 victory tonight in Memorial Stadium.

Nolan said he didn't know that the bases were loaded until he came into the clubhouse and began accepting congratulations from his teammates.

While Nolan's heroic blast provided the evening's most exciting moment, the best performance was turned in by winning pitcher Dennis Martinez (12-10), who went the full 10 innings (132 pitches) and allowed only four hits. Martinez allowed no hits in eight of those innings.

After retiring the first nine Toronto batters, Martinez gave up three singles and two runs in the fourth. Errors by Eddie Murray and Glenn Gulliver in the fifth gave the Blue Jays an unearned run that tied the game, 3-3, after Murray's three-run homer in the first had given Baltimore a 3-0 lead.

Beginning in the sixth, Martinez retired 14 straight until two were out in the 10th and Buck Martinez singled to left.

Toronto starter Dave Stieb pitched nine innings, but reliever Joey McLauglin (8-6) came in to pitch the 10th.

McLaughlin walked Ken Singleton on five pitches and Murray -- who had three hits -- on four to start the inning. John Lowenstein's second consecutive sacrifice bunt moved the runners into scoring position, and, with first base open, McLaughlin walked Cal Ripken Jr. intentionally to load the bases.

Jim Dwyer struck out, bringing a moan from the crowd of 12,139. The frustration built even more when Nolan, who unsuccessfully pinch hit in the eighth for Rick Dempsey with runners on first and second, fell behind, no balls and two strikes.

"It didn't surprise me that he was getting out of trouble, because I've seen Joey get into and out of those types of jams lots of times before," said Nolan, a longtime friend of McLaughlin.

But McLaughlin, who had thrown Nolan three straight breaking pitches, tried a fast ball on the fourth pitch.

"The pitch looked awful big coming up to the plate," Nolan said of the letter-high ball that he hit barely into the right field bullpen. "The way things had been going, I would have popped up that pitch or fouled it back. I really haven't produced the way I should have this year. So I'm glad to give the team a lift."

The Orioles needed some kind of lift at the plate, having stranded runners in the first, fourth, fifth, sixth and eighth. "The hitting has been dragging all year," Nolan said. "It's got to come around if we're going to catch Milwaukee."

Martinez's one troublesome inning and poor fielding by two of his teammates nearly ruined the first game of this homestand for the Orioles.

Damaso Garcia, the American League leader in hits, led off the fourth with a bloop single to right. (Garcia, who has hit safely in 107 of 121 games he has played this season, is threatening Al Simmons' record of 133 games hit safely). Garcia went to third on Hosken Powell's single, and scored Toronto's first run on Willie Upshaw's single to center.

Powell, who went to third--he and Garcia took an extra base on Al Bumbry's weak throwing arm--scored the second run on an infield ground out by Lloyd Moseby.

The Blue Jays tied the game in the fifth on an unearned run. Murray committed a three-base error on a routine grounder by Al Woods. Murray failed to field the ball cleanly, and his throw into the dirt to Martinez, covering the base, was kicked by Woods into right field. Glenn Gulliver misplayed Buck Martinez's grounder, trying to look Woods back to third, allowing the run to score.

But then Martinez began his second unhittable streak of the night, giving Nolan and the Orioles all the time they needed.