A's prepare to challenge Astros for AL West lead

OAKLAND, Calif. -- The Houston Astros will turn to their hottest pitcher, left-hander Dallas Keuchel, when the Oakland Athletics make a bid to move into a tie for first place in the American League West on Saturday afternoon.

On Friday night, Oakland's Nick Martini tied the game with a ninth-inning double and Matt Olson won it with a leadoff home run in the 10th, allowing the A's (73-49) to move within one game of the Astros (74-48) atop the West with a 4-3 triumph.

Keuchel (9-9, 3.43 ERA) was a 16-2 winner the last time he pitched in Oakland in May, and that was before he really got rolling.

The 30-year-old went 4-1 with a 1.65 ERA in five starts in July, and has yet to lose in August, going 1-0 with a 2.25 ERA in three outings.

He suffered an 8-1 shellacking at home in April in a game in which Oakland's Matt Chapman, Chad Pinder and Mark Canha homered.

He is 6-5 with a 2.78 ERA in his career against the A's, and Saturday's start will be his 21st meeting with Oakland, his 19th as a starter. Keuchel is 1-1 with 4.20 ERA in two starts against the A's this season.

Keuchel will have to deal with the knowledge that no matter how well he does, the A's might still prevail against the Houston bullpen.

Olson's homer in the series opener was Oakland's eighth walk-off hit of the season. The A's lead the majors in runs scored in the eighth inning, and Friday's ninth-inning run was their 54th of the season, tops in the AL.

Oakland is 11-5 in extra-inning games and a major-league-best 26-10 in one-run decisions. Each of the A's last four wins has been by one run.

A's closer Blake Treinen has helped close the door on most of Oakland's close wins this season. He was the winner in Friday's contest, holding the Astros scoreless in the top of the 10th before Olson's homer in the bottom of the inning.

The win was his sixth of the season. He's also recorded 32 saves.

The A's will counter Keuchel with right-hander Trevor Cahill (4-2, 3.39), who has struggled in two earlier meetings with the Astros this season.

Houston ran up an 8-4 home win over the A's in April when Cahill allowed four runs in six innings.

He later had to be pulled in the fourth inning of an eventual 6-4 A's win at Houston in July.

Cahill has gone 1-1 with a 5.82 ERA in four career games, including three starts, against the Astros.

Astros center fielder George Springer, who homered off Cahill in the April meeting, returned from a stint on the disabled list to go 1-for-5 in Friday's loss.

The Astros have held solo leadership in the AL West since June 14. Their biggest lead in the past two months was six games.

The A's, meanwhile, were 10 games out after a 6-5 loss at Houston on July 10. They have gone 22-8 since that date, while the Astros have struggled to a 12-16 mark.

Not counting the first month of the season, the A's haven't held or shared first place in the AL West since Aug. 25, 2014.