HOUSTON -- Astros pitcher Gustavo Chacin has given up 45 homers in his career, but he got to enjoy the feeling of touching them all himself on Monday afternoon.

Chacin socked a 1-1 pitch from Washington pitcher Luis Atilano down the right-field line and just over the wall for his first career home run in the bottom of the third. It was the first Major League hit for Chacin, but what made it even more shocking is that it came in his first at-bat in nearly five years.

"For sure, it surprised me," said Chacin, who hadn't stepped to the plate in a Major League game since June 26, 2006. "Like I said, I tried to get on base in that situation. That's all that was on my mind right there."

Chacin, who spent four seasons with the Blue Jays before being signed by the Astros to a Minor League contract prior to this year, was 0-for-7 at the plate in his career. He's the first Houston pitcher to hit a homer for his first Major League hit since Butch Henry (off Doug Drabek) in 1992.

He's the first Astros pitcher to hit a home run since Mike Hampton on July 24, 2009, and he's the fifth Houston relief pitcher to homer. Russ Ortiz (May 19, 2009) was the last Astros relief pitcher to hit a home run.

"He's got more home runs than me and [Jeff] Keppinger put together already in one swing of the bat," said center fielder Michael Bourn, who got his first triple of the season on Monday.

Chacin tossed 2 2/3 innings in relief of Roy Oswalt, who was thrown out of the game in the third inning. The fact the Astros lost, 14-4, outweighed any personal satisfaction Chacin got from hitting a home run.

"My job is pitching, not hitting," he said. "But it's nice to hit the home run. It's real nice."

Chacin said he didn't retrieve the ball.

Moehler to start Thursday

HOUSTON -- Brian Moehler, who gave up 10 hits and eight runs in 2 2/3 innings in Saturday's 12-2 loss in Cincinnati, will start Thursday's series finale against Washington, manager Brad Mills said on Monday. Moehler is 0-2 with a 7.29 ERA in 13 games, including one start.

Mills said Moehler will benefit from having four full days to prepare himself and mentally and physically to make the start.

"It's going to be nice. Now, he has these days to prepare for that start on Thursday," Mills said. "He can look forward to that start. It's not a day down the line or two days. It's four days before he starts, so he knows, and we'll go from there."

Mills said the club also considered left-hander Wesley Wright for Thursday's game.

"But that's why [Moehler] is here, because he's able to adapt to do so many things," Mills said. "He's been with us all year, and that was one of the biggest reasons he's been given that role is that he's able to do this. It's his role, he's prepared for it, so let's give it to him."

Memorial Day meaningful for Wade

HOUSTON -- There are few bigger supporters of the military than Astros general manager Ed Wade, who has a son in the Navy, and two weeks ago, he traveled to Annapolis, Md., for the funeral of former Navy captain Jack Fellowes, who was held as a prisoner of war in Vietnam for 6 1/2 years.

The Astros and Nationals wore special caps during Monday's game to commemorate Memorial Day.

"It's nice that one out of every 365 days we actually stop and think about what these guys are doing 365 days a year to protect us," Wade said. "Bobby Forrest, our [vice president for ballpark operations], has a son that is a Marine currently in Afghanistan, and I walk past Bobby every day and think about what's going through Bobby's head, not knowing where his son is or knowing what's going on."

Wade said his son, Ryan, will be promoted to lieutenant in the Navy from lieutenant junior grade on Tuesday.

"We're fortunate we get to play a baseball game today," Wade said. "The most stressful thing we have to deal with is if we're going to have to score runs or not. There are a whole lot of guys and women in Iraq and Afghanistan and other dangerous places making sure that's the only thing we have to worry about today."

Sullivan making most of opportunities

HOUSTON -- Cory Sullivan began Monday leading the Majors in pinch-hit appearances with 32 and was tied for seventh in the National League with five pinch-hits. He worked a key walk as a pinch-hitter in the 10th inning on Sunday in Cincinnati and scored the go-ahead run.

"Any at-bat you get in a game is good," Sullivan said. "Pinch-hitting, hopefully you're not always getting at-bats that matter, not that you don't enjoy those -- getting the opportunity to get on base and give the team a chance to win. But it just means you're getting a chance to play and have an opportunity to get at-bats."

Sullivan entered Monday with four hits in his past 13 pinch-hit at-bats, and feels like he's getting more comfortable as the season progresses.

"I feel like early in the season, you get to set the groundwork for later in the season, where the at-bats in August and September will matter a little bit more," he said. "You've got that confidence to build off of."