The top three men in Houston's lineup combined to go 5 for 6 with six runs scored. Leadoff man Michael Bourn went 3 for 3 with a stolen base and three runs scored, Kaz Matsui walked three straight times and scored a pair of runs, and Hunter Pence had two hits and two RBI.
Pence leads the team with 11 RBI this spring.
"Kaz with the three walks was huge," Astros manager Brad Mills said. "That's one thing we haven't been able to do a lot of this spring. You put those behind Michael's three hits, that's how you get started."
Marquis allowed the first four batters to reach base during a five-run first inning. He gave up eight total hits and struggled with his command, walking four. His ERA rose to 21.94.
"None of my pitches worked," he said. "I just didn't have a feel for anything."
Marquis, who signed a two-year, $15 million deal in December, went 15-13 with a 4.04 ERA with Colorado last season. He logged over 200 innings for the third time in his career and appeared in his first All-Star game.
The Nationals hope that either Marquis or John Lannan will anchor their rotation.
Marquis said he plans on throwing two bullpen sessions before his next outing. He is confident he can get himself right by the time the regular season rolls around.
"You still want to see results," Marquis said. "You don't want to embarrass myself or embarrass my team with results like that. I'm a competitor."
Wandy Rodriguez limited the Nationals to two runs on four hits over four innings. His only two mistakes came on home runs to Wily Taveras and Josh Willingham. He struck out seven and didn't walk anyone for the second straight start. Last time out, Rodriguez allowed six runs in three innings against the Marlins.
Cristian Guzman started for the Nationals at shortstop for the first time this spring. He's recovering from offseason shoulder surgery and had missed some time earlier this spring after his wife gave birth to his daughter. He went 1 for 4 with a triple, showing off some blazing speed on the base paths.
Taveras was the only Nationals player with more than one hit, going 2 for 3. Justin Maxwell, a prospective replacement for former starting right fielder Elijah Dukes, who was released on Wednesday, went 0 for 3.
Nationals reliever Matt Capps gave up a run and walked two in an inning of work. Drew Storen also allowed a run in an inning of work.
Nationals pitching prospect Stephen Strasburg is scheduled to make his third start on Friday against the Cardinals. ... In addition to Dukes, the Nationals also released reliever Logan Kensing. ... The Astros optioned pitchers Fernando Abad, Evan Englebrook, Matt Nevarez, Polin Trinidad, Jose Valdez and Henry Villar, infielder Wladimir Sutil and outfielders Brian Bogusevic and Yordany Ramirez to minor league camp.