The Houston Astros haven't won many series this season. Heck, they haven't many games.

That is why their 6-3 loss to the Pittsburgh Pirates on Wednesday night was a little tougher for the Astros to take than many of the 95 they have suffered this season.

The Astros had a chance to win the three-game series against a team contending for a playoff spot, but couldn't overcome a poor start from left-hander Fernando Abad.

Abad (0-3) was rocked for six runs — five earned — in four innings.

"I thought Abad could give us a chance, but unfortunately we got down again early," Astros interim manager Tony DeFrancesco said. "It's getting frustrating for us."

The loss dropped Houston 53 games under .500 at 42-95, easily the worst record in baseball.

Pittsburgh scored two runs off Abad in the first and another in the second to take a 3-0 lead. Garrett Jones and Sanchez hit consecutive RBI singles in the first and Holt singled in a run in the second.

After Houston got its lone run in the fourth when Jimmy Paredes doubled and scored on Brian Bogusevic's single, Pittsburgh answered with two runs in the bottom half off Abad to make it 5-1. Presley tripled in a run and scored on Holt's sacrifice fly.

"After the first inning, I was better in the second and third innings," Abad said "Then I tried to use my breaking ball and my sinker in the fourth inning and they didn't work."

Kevin Correia and Presley, who were filling in for injured Pirates, made big contributions.

Correia pitched six solid innings, and Presley had two hits and scored three runs to help Pittsburgh gain ground in the NL wild-card race.

"At this time of year, it's all about winning," Presley said. "You need everybody doing everything they can do to help the team win."

Correia stepped into the Pirates' rotation for right-hander Jeff Karstens, who injured his right hip Friday in a start at Milwaukee.

Correia allowed one run and four hits. He also walked one and struck out one.

Correia (10-8) pitched four scoreless innings of relief against the Brewers in the game in which Karstens was injured. Correia began the season in the starting rotation but was bumped to the bullpen when the Pirates acquired left-hander Wandy Rodriguez from the Astros in a trade on July 24.

Presley was playing in place of left fielder Jose Tabata, who bruised his left foot on Tuesday night when he fouled a pitch off it and still felt pain after taking batting practice before Wednesday's game.

Pirates rookie Brock Holt had two RBIs one night after getting four hits in his fourth major league game, and Gaby Sanchez had three hits for Pittsburgh, which pulled within 1 1/2 games of St. Louis in the race for the second wild-card spot.

A squeeze by Clint Barmes brought home a sixth-inning run for the Pirates.

Brandon Laird, yet another injury replacement, provided Houston's highlight with his first major league home run, a two-run, two-out shot in the ninth inning off Jason Grilli. Laird took over at third base in the sixth inning when Scott Moore strained his right groin while fielding a bunt by Holt.

Laird struck out swinging in his first at-bat in the seventh inning against Jared Hughes but was more prepared in the ninth.

"Everybody always tells me, be ready and that's what I was," Laird said. "I went in there and the first at-bat chased a couple bad pitches. I just wanted to go up there right there and see it before I swung and that's what I did and got a good swing on it."

DeFrancesco was happy for Laird, who was claimed off waivers from the New York Yankees last week.

"That was really neat to see," DeFrancesco said. "That was a real bright spot."

NOTES: Houston RF Fernando Martinez (skin irritation) was a late scratch and replaced by OF J.D. Martinez. ... Pittsburgh 2B Neil Walker (lower back stiffness) missed his ninth straight game, and wasn't expected to return Friday night for the opener of a three-game series against the Chicago Cubs as originally hoped. ... RF Travis Snider (strained right hamstring) sat out after being injured running the bases Tuesday but hopes to play Friday. ... Houston expects SS Jed Lowrie (sprained right ankle) to begin an injury rehabilitation assignment this weekend after being on the disabled list since July 15 with a sprained right ankle. ... Both teams are off Thursday. On Friday night, Pittsburgh RHP A.J. Burnett (15-5, 3.63) will face Cubs LHP Travis Wood (4-11, 4.64), while Houston RHP Lucas Harrell (10-9, 3.81) will oppose Reds RHP Hector Bailey (10-9, 4.09) in the first game of a three-game series at Cincinnati.