The Seattle Mariners failed to keep pace in the wild-card race after getting shut down by the Houston Astros last time out.
They'll try to quickly regroup Wednesday night as these AL West rivals wrap up a three-game set in Seattle.
The Mariners (79-65) took Monday's opener 4-1 before falling 2-1 the following day, their second one-run defeat in three games. Logan Morrison provided all the offense with a game-tying homer in the eighth inning before Yoervis Medina gave the lead back in the ninth.
Seattle fell one-half game back of the AL's second wild-card spot.
"I like where we're at," Morrison told MLB's official website. "It's a tough loss, but shoot, that's why we play 162."
Houston's Jonathan Villar delivered a two-out tiebreaking single and Collin McHugh combined with reliever Josh Fields on a two-hitter. The Astros (64-81) have won seven of nine behind a 2.04 ERA.
"They have the confidence and they know they can win, and when you can have that, you come out ahead a lot of times," interim manager Tom Lawless said. "It's somebody different every night contributing something to the W, and that's really important for a team."
Houston's victory was just its third over an 11-game stretch against the Mariners.
Hisashi Iwakuma (14-6, 2.97 ERA) takes the ball for Seattle looking to win a sixth consecutive decision. However, the right-hander hasn't been very sharp of late, posting a 7.24 ERA in his last three starts.
Iwakuma gave up three runs and seven hits over 5 1-3 innings to win 7-5 at Texas on Friday.
"I felt good in general," he said after throwing just 84 pitches. "I thought I had good arm action, I thought my pitches were working. It was a tight strike zone but I thought I did well overall."
Iwakuma is 4-0 with a 2.31 ERA over a five-start stretch against division foes. He's also gone 5-1 in his last six home starts while striking out 37 and walking one over 42 1-3 innings.
Iwakuma threw six innings of one-run ball to win 13-2 at Houston on July 1, improving to 4-1 with a 2.43 ERA in his last six appearances in the series. Jose Altuve is 8 for 19 in their matchups, but Chris Carter and Jason Castro are a combined 7 for 38 with 13 strikeouts.
Altuve is hitless in seven at-bats over the last two days and 2 for his last 17 in the series. Carter has hit safely in eight straight overall, going 11 for 28 with three homers and seven RBIs.
Nick Tropeano will be called up from Triple-A Oklahoma City for his big league debut as Houston goes to a six-man rotation. The right-hander went 9-5 with a 3.03 ERA over 23 minor league games - 20 starts - while striking out 120 over 124 2-3 innings.
"It's a great experience," general manager Jeff Luhnow said. "He pitched a full year, so he doesn't need a lot of innings. We need to be careful not to overuse him. We do want to see how he performs against big league hitting. It's an exciting opportunity for him, and it gives our guys a little bit of a breather."
Mariners outfielder Dustin Ackley, mired in a 1-for-19 slump, is expected to miss a fourth consecutive game with an injured left ankle.
Seattle has dropped four of its last six at home.