AP Sports Writer
OAKLAND, Calif. (AP) -- After getting a taste of a pennant race as a late-season call-up last year, Martin Perez looks nothing like a rookie this time around.
Perez allowed one run in seven innings to win his sixth straight start and Mitch Moreland homered to move the Texas Rangers back into sole possession of first place in the AL West with a 4-1 victory over the Oakland Athletics on Tuesday night.
"He's grown leaps and bounds really," manager Ron Washington said. "It's maturity. The experience he had last year up here helped him tremendously. He realized he can pitch up here and he just goes out there and pitches. Right now a lot of good things are happening for him."
Perez made six appearances after being called up last September and lost twice to the A's to help Oakland steal the AL West title from Texas. Perez (9-3) is doing his best to win that title back this year.
After falling into a tie for first with the A's when they lost the series opener, the Rangers bounced back and are assured of leaving Oakland for the final time in the regular season with at least a share of the division lead.
"When you come the first time, you don't have too much of an idea, how the game is here," Perez said. "It's the same ball, but a lot of guys have more experience than you. I just tried to learn last year and this year too. Every day you learn something new. You have to have a plan for the game. ... I just want to continue."
Bartolo Colon (14-6) allowed three unearned runs in the fifth inning following his own error and missed an opportunity to become first pitcher to reach 20 career wins against Texas. Colon is winless in five starts since July 26 with a DL stint in the middle of that stretch.
The highlight of the game for Oakland came in the sixth inning when third baseman Josh Donaldson raced across the vast foul territory at the Coliseum and leaped over the tarp to make a backhand catch to rob David Murphy.
"You're not going to see too many plays better than that," manager Bob Melvin said.
That spectacular play came after a poor decision earlier in the game that squandered a prime scoring chance for Oakland. Donaldson was on second with two outs when Yoenis Cespedes hit a grounder into the hole between third and shortstop. Jurickson Profar got to the ball but held onto it as he had no play at first. Donaldson ran through coach Mike Gallego's stop sign and was easily thrown out at home despite barreling into A.J. Pierzynski.
"For some reason I thought I heard 'go,'" Donaldson said. "I know it wasn't Gags because as soon as I took two steps he was saying, 'Stay here, stay here.' It ended up being a really bad play for us and for myself."
Oakland didn't threaten again off Perez and lost for just the second time in its past nine games.
Colon, making his second start back from a strained left groin, stranded runners on third with less than two outs in the first and third innings. But he lost the lead on Moreland's solo homer with two outs in the fourth.
The Rangers struck for three unearned runs in the fifth inning to take a 4-1 lead with help from two comebackers that Colon could not handle. The rally started when Craig Gentry reached on an error with one out when his grounder popped out of Colon's glove. Gentry scored on Profar's double into the right-field corner that rookie Michael Choice bobbled.
Ian Kinsler followed with another comebacker that hit off Colon's glove and was ruled an infield single. Adrian Beltre added a run-scoring groundout and Pierzynski blooped an RBI single.
"The one play that made the difference was the groundball hit to me that I dropped," Colon said through an interpreter. "It was a routine play."
Alex Rios added a leadoff homer in the eighth to make it 5-1.
Perez followed up his perfect August by winning again to start September, shutting Oakland down after Coco Crisp doubled and scored on Jed Lowrie's sacrifice fly in the first.
Perez became the first Texas pitcher to win six consecutive starts since Kenny Rogers won eight straight in 2005. His last four wins have come against All-Star pitchers, outdueling Seattle's Felix Hernandez twice and Chris Sale of the Chicago White Sox once.