A seat at the back of the rotation has helped Jon Garland vault himself and the White Sox to the head of their classes.

Garland, the Sox's No. 5 starter, joined Seattle's Jamie Moyer as the only four-game winners in the American League as the Sox extended their winning streak to eight games by beating Oakland 6-0 Monday night at the McAfee Coliseum.

Despite a lack of run support until the seventh inning, Garland was in command from the outset. He scattered four hits and walked only one batter in pitching the third complete game of his career. His only other shutout came Aug. 28, 2002, vs. Toronto. Garland (4-0) lowered his ERA to 1.80. He hasn't yielded a home run in his last 25 innings.

"He deserved it," manager Ozzie Guillen said of his decision to let Garland finish the game with left-hander Damaso Marte warmed up in the ninth. "Besides, we let the bullpen rest.

"[Garland] has matured, and he knows what he has to do. He doesn't beat himself."

The Sox extended their lead in the AL Central to five games, the largest since finishing the 2000 season with a division title by the same margin. The last time the Sox won eight straight was July 18-25, 2003.

Garland was locked in a scoreless duel with left-hander Barry Zito until the seventh, when the Sox came up with their latest surprise.

It came in the form of backup catcher Chris Widger, who pulled a two-run homer over the left-field fence. Widger's last home run had come Aug. 9, 2000, as a member of the Seattle Mariners off the Sox's Mike Sirotka.

"A guy in my position, you don't try to hit a homer any time, much less against a guy who throws like that," Widger said. "Sometimes you can't explain why it happens. When the team is playing well, unexpected people step up and do things like that."

Widger was starting in place of A.J. Pierzynski, who was nursing a sore right toe and was hitless in 12 career at-bats against Zito. Pierzynski managed to retrieve Widger's home run ball from a fan.

"That ball probably means as much to me as the first one I hit, just because of what I've done and the places I've been over the last few years," Widger said.

Widger has been just as instrumental behind the plate; the Sox's pitchers have posted a 1.00 ERA when he has caught.

Garland pitched efficiently, having a runner in scoring position in only two innings and retired the final 13 batters he faced.

Garland's success also helped the Sox take a major step toward reversing their failures in Oakland. The victory was only their third in their last 18 games at McAfee, and a win in either of their next two games would give them their first series victory in Oakland since taking two of three Aug. 28-30, 2000.

Garland's 116 pitches were the most by a Sox starter this season. He joined ace Mark Buehrle as the only staff members to throw complete games this season.

The biggest difference in Garland from the last three seasons, when he won 12 games apiece but his ERA rose, is his poise and confidence.

"I'm throwing a lot more strikes, and when guys get behind, they can't sit on my pitches," said Garland, who lowered his ERA to 1.80.

His most serious jam occurred in the third when he faced Eric Chavez with runners at first and second, but he induced Chavez to ground out to second to end the inning.

Garland also retired Mark Kotsay on a fly to center with Marco Scutaro at second to end the fifth.

Third baseman Joe Crede left in the bottom of the seventh because of a bruised right forearm.

Oakland hasn't scored in its last 22 innings.

mgonzales@tribune.com

Associated Press contributed to this report.