The left-hander is just happy he could end a two-game Boston slide, help the Red Sox finish a road swing on an upbeat note and get his team out of last place in the AL East.
Lester improved to 14-0 all-time against Baltimore with eight dominating innings, Dustin Pedroia hit a tiebreaking infield single and the Red Sox averted a sweep with a 6-2 victory over the Orioles on Thursday night.
"If I knew the answer to that, I'd do well against everybody," Lester said, shaking his head. "I just pitch well against this team. ... I just really don't know. I'm aware of the track record I have against them, but I don't know how to explain it. I feel comfortable against them. I really like pitching here at this park, I've always felt good here."
Lester (3-1) is unbeaten in 17 career starts versus the Orioles and boasts the longest active winning streak by any pitcher against one team. He yielded two runs on four hits, walked three and struck out five.
"He threw his changeup about as good as he's ever thrown," Red Sox manager Terry Francona said. "Some of those hitters, he really slowed them down. He was really good and he needed to be to give us enough time. He gave us a chance."
It was 2-all when Carl Crawford doubled off Jim Johnson (1-1) to the start the seventh. Crawford held second when Marco Scutaro couldn't execute a sacrifice bunt, took third on Jacoby Ellsbury's grounder and scored when third baseman Mark Reynolds bobbled Pedroia's slow roller.
Baltimore fell into last place in the AL East, a half-game behind the Red Sox, who finished 6-3 on a nine-game road trip.
"It's great to finish up this road trip the way we did," Lester said. "The guys are starting to feel a little bit better about themselves now, and hopefully we can go home and really start playing well. To go 6-3 on this road trip, well take it, the way we started off the season."
Boston's Adrian Gonzalez had three hits and two RBIs.
Ellsbury led off the game with a double and scored on Gonzalez's one-out double for a 1-0 lead.
The Orioles tied it in the bottom half when Brian Roberts drew a leadoff walk, moved to second on Nick Markakis' single, stole third and scored on Lee's single, which ended an 0-for-14 slump with runners in scoring position.
Ellsbury and Gonzalez teamed again to put the Red Sox up 2-1 in the third. Ellsbury singled with one down, moved to second on a groundout and came home on Gonzalez's single.
Guerrero tied it in the sixth with a shot to left off a full-count fastball from Lester, who surrendered a home run for the first time in five starts. It was Guerrero's fourth homer of the season.
Baltimore starter Brad Bergesen went six innings, allowing two runs on six hits. He walked two and struck out five.
"The body of work was pretty good. I thought [Bergesen] gave us a good chance to win against a good-hitting club, and I was proud of him," Orioles manager Buck Showalter said.
Bergesen escaped a jam in the sixth when Gonzalez's double put runners on second and third with no outs. He fanned Kevin Youkilis and David Ortiz, issued an intentional walk to J.D. Drew to load the bases and then got Jarrod Saltalamacchia to fly out to the warning track in center.
"I was facing a tough lineup like that and you know Lester, his career against the Orioles -- I knew just every pitch mattered tonight," Bergesen said. "I think the biggest thing for me was the sixth inning, getting in that jam and being able to get out of it."
In the eighth, the Red Sox loaded the bases with none down before Saltalamacchia's RBI single off Michael Gonzalez made it 4-2. Two outs later, Ellsbury looped a two-run single to center.
Ellsbury and Gonzalez have each doubled in four straight games. ... Orioles LHP Brian Matusz, on the 15-day disabled list since March 30 with a strained left intercostal muscle, is headed to the team's Sarasota, Fla., facility after throwing a pain-free 35 pitches from the mound in a bullpen session before Thursday's game. ... Baltimore SS J.J. Hardy, who has been on the 15-day DL since April 10 with strained left oblique, took dry swings, hit off a tee, threw from 120 feet and ran sprints in Sarasota on Thursday. Showalter said Hardy was scheduled to take ground balls Friday. ... The Rays-Red Sox game postponed by rain April 13 will be made up as the 1:05 p.m. portion of a day/night doubleheader at Fenway Park on Aug. 16. ... RHP Chris Jakubauskas (right groin strain) will pitch for the Orioles' Triple-A Norfolk affiliate Sunday as part of a rehabilitation assignment. He is eligible to come off the 15-day disabled list May 2. ... Baltimore is 1-11 when scoring three runs or less.