ARLINGTON, Texas -- Coco Crisp and Khris Davis got Oakland off to a quick start against Yu Darvish. Ilkay Gundogan Jersey . Then came their big blows against a hard-throwing reliever to clinch the fourth series in a row for the Athletics.Crisp and Davis both hit two-run homers in the eighth off Matt Bush and the As beat the AL West-leading Texas Rangers 6-4 on Wednesday night.Davis had also homered in the first off Darvish, after Crisp led off the game with a triple into the right-field corner and scored on Jed Lowries sacrifice fly.I think we all enjoy playing with each other, that were going to get the job done, Davis said. Theres a loose relax-ness in the clubhouse before the games. Its a good chemistry. Winning creates that.While still eight games under .500 for the season, the As (47-55) have won nine of 13 games since the All-Star break. They have won four series in a row for the first time since May 2014, and they havent lost to Darvish in more than four years.I know your records your record, but we feel like we should have a better record. Now some guys that started off really cold are swinging the bats a lot better, manager Bob Melvin said. And now weve got a couple players in here that have brought some enthusiasm, playing hard, fighting for their jobs, want some playing time.Ryan Dull (5-2) threw 1 1/3 perfect innings in relief of Sean Manaea, who struck out nine without a walk in 6 2/3 innings. Ryan Madson worked the ninth for his 22nd save in 28 chances, two nights after giving up Adrian Beltres game-ending homer in the series opener.Darvish, 1-8 in 11 career starts against Oakland with that win coming May 16, 2012, struck out six without a walk. He left with a 3-2 lead after retiring 16 of the last 18 batters he faced, striking out Davis on a breaking pitch to end the sixth with a runner at third.Hes solid. You go out there, you know youre going to be in a battle, Crisp said.Ian Desmond hit his 20th homer for the Rangers, a two-run shot in the fifth that put them ahead 3-2. That came two innings after the All-Star center fielder had a two-out double and scored on Beltres single.Crisps homer in the eighth was on a 99-mph fastball from Bush (3-2) that put the As up 4-3. Davis second homer of the night, and 25th of the season, came on a 97-mph heater.The ball was up and center-cut, Rangers manager Jeff Banister said. Hes usually down. .