It was the first time in 88 days that Mike Flanagan had to make a major decision: would he throw a fast ball or something offspeed to Chicago's Greg Luzinski, one of baseball's hottest hitters.

"We've been playing well and it was the first inning," Flanagan said later, "so I figured I'd take my chances."

Luzinski turned Flanagan's choice (a low fast ball) into a two-run, 430-foot homer to right center field that helped the White Sox to a 4-3 victory over the Orioles at Memorial Stadium today.

It give Flanagan his first loss this year, after six victories.

Flanagan, who suffered ligament damage in his left knee May 17 while fielding a grounder against Chicago, wore a brace today and pitched 4 1/3 innings. Baltimore Manager Joe Altobelli said Flanagan will probably start again in five days, at Chicago.

"It went pretty much like I expected it to," Flanagan said. "The thing I've been worried about all this time was that while I was pitching I would think about the brace. But the brace was fine. It's not just the knee, it's not having pitched in three months. I felt okay . . . I was pleased with the stuff I had."

Flanagan left the game in the fifth inning, still trailing, 2-0, after giving up leadoff singles to Marc Hill and Julio Cruz. It was actually a decision by right fielder Dan Ford that led to Chicago's winning run. With Cruz on first and Hill on second, Rudy Law hit a fly ball to medium-deep right field. Instead of hitting the cutoff man--the Orioles' infielders weren't even lined up for a play at third--Ford threw to third base and came nowhere close to getting Hill. Ford's throw allowed Cruz to take second, putting both runners in scoring position. Since Law's fly ball came on Flanagan's 70th pitch, and the plan was for him to go no more than five innings or 70 pitches, Altobelli brought in Sammy Stewart.

Stewart got Scott Fletcher to ground out, but gave up a two-out, two-strike single to Tom Paciorek that scored both runners. Both runs were charged to Flanagan, and they gave the White Sox a 4-0 lead.

Ford's move didn't seem too important until the ninth inning; Ken Singleton hit a two-out, two-run homer--only his second from the right side this season--off reliever Juan Agosto that made it 4-3. With Baltimore having staged two-out comebacks the last two nights--even though the Orioles didn't win Saturday--against the White Sox, most of the 24,384 stayed put. But Dennis Lamp came on to retire Gary Roenicke to end the game.

LaMarr Hoyt, who pitched 6 1/2 innings, won his 14th game of the season, tying him for the American League lead with Baltimore's Scott McGregor and Texas' Rick Honeycutt. The home run by Luzinski was his 23rd of the season, tying him with rookie Ron Kittle for the club lead.

Hoyt pitched to the minimum number of batters (15) through the first five innings. John Lowenstein singled in the second and fifth innings, but each hit was followed by a double-play grounder by Singleton.

"I had been giving up a lot of home runs lately," Hoyt said. "Plus, the sun was so bright the ball was only a reflection. Our hitters said they were having trouble seeing the ball, so I figured their hitters were having problems, too."

"After each one of them, I came back and pitched harder," Hoyt said. Finally, in the sixth, Joe Nolan, Todd Cruz and Al Bumbry hit Hoyt for consecutive singles to load the bases. And Ford's sacrifice fly scored Nolan to cut Chicago's lead to 4-1. But Agosto came on to pitch to Cal Ripken, who hit two balls into the left field bleachers--barely foul--before taking strike three.

The White Sox, in first place in the American League West, won two of the three games here, three of four against the Yankees and two of three against Detroit. They are starting to destroy the notion that East teams are superior.

"We can play with anybody--East or West," Paciorek said. "Fortunately, we're in the West and the other teams aren't playing well right now. All I can say to the teams in the East is, 'Tough luck.' "