ARLINGTON, Texas -- Another night, another dramatic win for the Texas Rangers.

A ninth-inning uprising Monday night that ended with first baseman Mitch Moreland's sacrifice fly lifted the Rangers past Houston Astros 6-5 and into first place in the American League West for the first time in 2015.

"It's been a lot of fun here lately," Moreland said. "We just keep getting better, it seems like. We've got a key pieces and a lot of guys that have stepped up and contributed big for this team. Everybody in that clubhouse is helping us win ballgames and get us to where we're at right now. And we're not finished."

The second of four games between the Lone Star State rivals at Globe Life Park this week had all the atmosphere of a playoff contest. The lead went back and forth early, as both starters struggled with their command.

Each bullpen settled down before the Rangers mounted the game-winning rally in their last at-bat. Designated hitter Prince Fielder started it with an opposite-field single off reliever Oliver Perez (0-2) to lead off the ninth.

Houston manager A.J. Hinch turned to the seventh reliever of the evening, Will Harris, who promptly gave up a single to third baseman Adrian Beltre. Pinch runner Drew Stubbs, in for Fielder, went to third.

Moreland followed with a line drive that center fielder Jake Marisnick caught, but his throw was off line and Stubbs scored easily to give Texas the walk-off win.

"I was just trying to get something in the outfield," Moreland said. "He's a tough pitcher. You have to tip your cap to Prince getting it going."

Harris was also on the mound Monday night when he gave up Fielder's tiebreaking two-run homer in the eighth.

"We asked a lot out of our bullpen today," Hinch said. "Hard-fought game on both sides. Tough one to lose. Our guys battled. We battled on both sides of the ball. Proud of our guys for coming back after the four-spot in the first by them. The bullpen was almost perfect."

The Astros (77-68) had held the division's top spot for 139 days this season. The Rangers (77-67) are now on top by a half-game.

Houston, out of first place for the first time since July 26, is just 4-10 against Texas this season.

"We have some work to do," Hinch said.

The Rangers' surge has some historic overtones. Texas is just the sixth team to take over first place for first time in game 144 or later since 1969, according to Elias Sports Bureau. Only five teams in the past 40 years have won their division after trailing by at least 8.0 games in August, according to Elias.

"I really believe it's a belief system in place, it's a mind-set that this ball club has," Texas manager Jeff Banister said. "They have fought, scratched, clawed all ways imaginable to get to this point. We're not done yet. Still have a long ways to go."

The two starters -- Texas' Derek Holland and Houston's Collin McHugh -- both gave up five runs and didn't factor in the decision. Rangers closer Shawn Tolleson (6-3) worked the ninth and picked up the win.

Texas touched up McHugh for four runs in the first. The Rangers took advantage of a walk, hit batter, two steals and four singles, a couple being well-placed.

Fielder, facing a left-handed shift, drove home the first run with a roller through the hole left open at short. Beltre followed with a run-scoring blooper to right that second baseman Jose Altuve nearly tracked down.

A groundout by second baseman Rougned Odor and soft liner to right by shortstop Elvis Andrus drove in the final two runs of the frame.

Holland didn't take advantage of the early cushion by giving three runs back in the top of the second on three hits, a walk and hit batter.

First baseman Chris Carter doubled to plate left fielder Colby Rasmus. Catcher Hank Conger followed with an RBI single, and Marisnick laid down a perfect squeeze bunt to finish out the scoring.

The Astros climbed all the way back and took a 5-4 lead in the fourth on designated hitter Evan Gattis' two-out, bases-loaded single off Holland.

In the bottom of the inning, Beltre's two-out double into the left field corner scored a chugging Fielder from first base to tie the game and chase McHugh.

"He never really could finish hitters," Hinch said.

NOTES: The Rangers and the Chicago Cubs came into Tuesday with the largest increase in wins over last season at nine. The Houston Astros were third at plus seven. ... Rangers LHP Derek Holland was the fourth consecutive left-handed starter the Astros faced. Texas is scheduled to throw LHP Martin Perez on Wednesday. ... Rangers manager Jeff Banister said that Mike Napoli would be the regular left fielder against left-handed pitchers. Napoli has been primarily used at first base since the Rangers reacquired him. ... The Rangers-Astros game in Houston on Sept. 26 was selected as a FOX National telecast, with game time moved from 6:10 p.m. CT to 12:05 p.m. CT.