ARLINGTON, Texas (AP) -- The sun finally peeked through the clouds and a rainbow appeared beyond center field soon after the Texas Rangers finished playing.

All around, it was a bright ending to a drizzly Sunday.

Matt Harrison came within one out of a complete game for his 17th victory and the Rangers beat Seattle 2-1, adding to their AL West lead over Oakland for the first time in 10 days.

''The only thing we can do is keep winning series, and do what we've been doing the past month,'' Harrison said. ''The way they're playing, we've just go to keep going.''

On his 27th birthday, Harrison (17-9) became the fourth American League pitcher to 17 victories.

Adrian Beltre hit his 33rd homer and Mitch Moreland had an RBI double to back the All-Star lefty who has won nine consecutive starts against Seattle since May 2010.

''Glad we got two runs to support him a little bit,'' catcher Mike Napoli said. ''Overall, everything was pretty good. He had a good changeup, mixed in a couple of curveballs and backdoor sliders. For the most part, he was throwing strikes and missing barrels.''

With runners on first and third and two outs in the ninth, Koji Uehara struck out Michael Saunders to end the game. It Uehara's first save for Texas since being traded from Baltimore in July 2011.

The start of the game was delayed 2 hours and 12 minutes by rain. A light drizzle was still falling when Harrison threw the first pitch, and persisted through the game that took only 2 hours and 20 minutes to play.

Two-time defending AL champion Texas (87-59) has the league's best record, and now has a three-game division lead over Oakland. The A's lost for only the second time in 10 games Sunday, 9-5 at home against Baltimore.

Texas had a 5 1/2-game lead on Sept. 6 after winning at Kansas City, gaining a half-game that day on the idle A's. Before Sunday's games, that lead had shrunk to two games - the Rangers' smallest since April 13, a week into the season.

''They're playing unbelievable,'' Harrison said. ''We've just got to keep winning series.''

Texas has won eight of its last nine series, and hasn't lost consecutive games in more than a month.

The Rangers have their final off day of the regular season Monday. They start a three-game series Tuesday at the Los Angeles Angels, before spending next weekend in Seattle and then playing seven of their last 10 games against the A's.

Harrison scattered six hits and struck out five, and his only walk was to Franklin Gutierrez with one out in the ninth. After Kyle Seager's infield popout for the second out, Montero singled to right and manager Ron Washington made the pitching change after 119 pitches.

After allowing a single to start the game, Harrison didn't let a runner past first until Justin Smoak led off the eighth with his 16th homer. Harrison benefited from three double plays - two that he started.

''He did a good job coming in at both left-handers and right-handers, he works that changeup off the fastball, he's able to cut his fastball or sink it, rides it every now and again, a nice breaking ball,'' Mariners manager Eric Wedge said. ''He's got a quick tempo and helped himself, he's great defensively out there, a couple of big double plays. ''

Blake Beavan (9-10), pitching for the first time since Sept. 4, allowed two runs and seven hits over seven innings. The right-hander was the Rangers' first-round draft pick five years ago before being sent to Seattle in 2010 with Smoak in the Cliff Lee trade.

Beltre put the Rangers up 1-0 in the fourth with his eighth homer in 15 games. The 33 homers are one more than he had in his debut with the Rangers last season. The only time he hit more in his career was in 2004 for the Los Angeles Dodgers, when he led the majors with 48.

Murphy had a leadoff single in the fifth and scored when Moreland pulled a double into the right-field corner.

''We needed the home run from Beltre and we needed the double by Mitch,'' Washington said. ''Up and down our order, someone's going to get one.''

NOTES: The Rangers said after the game Martin Perez will start Friday's game at Seattle in place of struggling Scott Feldman. ... Seattle played its majors-high 24th rubber game of a series. The Mariners are 11-13 in those games, and had won seven of the previous eight. ... The Rangers are 16-7 in rubber games. ... The NFL's Dallas Cowboys played under sunny skies in Seattle, where they lost. ... During the rain delay, fans were able to see the start of both the Cowboys and A's games on split screen on the big video board. ... The announced paid attendance was 45,928, the 34th sellout at Rangers Ballpark. But a lot of bought tickets were unused on the wet day.