CHICAGO -- Are the Orioles allowed to think about the possibility of the postseason yet?
"I hope so," said reliever Darren O'Day, who arguably got the two biggest outs in Wednesday night's 4-3 win over the White Sox. "That's our goal from the beginning is to be there, and that's what you play the game for, to play in the playoffs."
The first-place Orioles aren't just inching there, they're in a downright sprint. Baltimore, already with wins in nine of its last 10 series, has been a baseball-best 31-13 since June 30 and extended its commanding lead in the American League East to 9 1/2 games with a three-game sweep over Chicago.
"We're really good as a team," said Nelson Cruz, who hit his league-leading 33rd homer as part of a trio of blasts. "We're doing the little things that that matter in the end. The pitching, the bullpen, it's amazing to see everybody do their job and go about their business.
The victory marked the O's first sweep in Chicago since taking a four-game set over the White Sox in 1995, and featured another fantastic outing -- this time by lefty Wei-Yin Chen -- which has become a trademark of the club's hot stretch.
"There were some things we weren't perfect with tonight, but when you pitch well, it can cover some things," manager Buck Showalter said of his staff, which has posted a 2.87 ERA since June 30. "When you catch the baseball, we played three good defensive games here."
And a a result, the Orioles, who have a league-leading 39 road wins, are a season-high 21 games over .500 and playing their best baseball of the season. What makes them such tough road team?
"Maybe we like coming to the ballpark later, sleeping in. I don't know," O'Day said. "Maybe it's the early wake-up call at home. Maybe it's our wives. Just kidding! No, I don't know. I really don't. But it's a good quality to have because when we get down the stretch, we're going to play some important road games, and in the playoffs, you obviously have to play on the road."
Chen, who has pitched better at home this season, turned in an impressive 7 1/3 innings, allowing three runs on six hits for his career-high 13th win.
"I would say everyone else is pitching better than me," Chen said, through his interpreter, of a rotation that has posted a 2.82 ERA over the last 17 road games. "But I think it's a really good competition out there. We all try to pitch better than each other."
After putting the Orioles in an early two-run hole on Avisail Garcia's first-inning homer, Chen watched his offense go to work as the O's raised their season total to 161 home runs.
Steve Pearce got things going, cutting the two-run deficit in half with a leadoff shot in the fourth inning. Pearce, who has heated back up on this road trip, extended his career high in homers to 13.
Adam Jones followed with a single and Cruz homered for the second time in three games on a line drive to left field to give the Orioles the lead. Jones added a solo shot, his 24th, to start the sixth inning.
"When we were coming in here, they were swinging the bats pretty good, so we sort of got fortunate and caught them on the other side," Showalter said of a White Sox lineup bolstered by Garcia's return. "It's hard to continue at that pace, but we scored just enough runs to win. That was tight tonight. There wasn't much margin for error."
Things got dicey when Chen, who needed just 80 pitches to get through seven innings, allowed a pair of one-out singles to end his night in favor of O'Day. The sidearmer struck out Jose Abreu and Garcia to keep the one-run lead intact and lower his season ERA to an astonishing 0.95.
"He's pretty amazing," Garcia said of O'Day. "He throws the ball really good, especially the slider because you see it in and he goes away. His pitches are really good. He made very good pitches."
Closer Zach Britton followed O'Day, recording his 27th save in 30 tries to put the finishing touches on the sweep.
Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Facebook and Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.