Villar homered on the first pitch of the game and Houston coasted to a 13-2 victory over the Seattle Mariners on Tuesday night.
The rookie connected off Joe Saunders, sending a drive well over the left-field fence for his first career homer. Houston scored six times in the first three innings to chase Saunders (11-14), then added seven runs in the final three to put the game out of reach.
"It definitely is contagious," Astros manager Bo Porter said about the offensive outburst. "You start to swing the bat and you start to see your teammates getting hits. It's one of those things where it's almost like pass the baton and guys are really seeing the ball well, laying off some tough pitches and then getting pitches that they can handle and putting good swings on them."
Altuve and rookie L.J. Hoes both had three RBIs. The total was a career high for Hoes, who entered with five RBIs in his 38-game career.
"Gives you kind of confidence," Hoes said. "You see these guys going up there getting hits. You feel kind of comfortable in the box because the guys in front of you did their job. When you come up with guys on second and third and less than two outs, you just know you've got to put a ball in play. Put a good swing on the ball and when you put a good swing on the ball, sometimes good things happen."
Meanwhile, starter Jordan Lyles (7-7) held Seattle in check through six innings. Lyles gave up two runs -- one earned -- and three hits while striking out five.
Franklin Gutierrez had a pair of RBI singles for the Mariners, who have dropped their last three games. They held a players-only meeting for approximately 20 minutes following the latest loss.
"It's about the internal fight that is in all of us and leaving it all out on the field," veteran Raul Ibanez said. "I think it was a collective thing. A couple veteran guys got together and we thought it was appropriate."
Saunders allowed seven hits and a walk in three innings. He has lost six of his last eight decisions.
Villar walked, stole two bases and scored during Houston's four-run third that broke the game open. Altuve and Matt Dominguez had run-scoring hits in the inning. Hoes capped the outburst with a two-run double that made it 6-1.
Houston had its way on the basepaths, successfully stealing bases on all five attempts against rookie catcher Mike Zunino. Altuve swiped three and has stolen a career-high 35 this season.
"That's the kind of night you wish you could have every night," Hoes said. "When everyone's clicking on all cylinders."
Altuve leads the majors with 21 hits in September. ... During the game, Seattle traded smooth-fielding shortstop Brendan Ryan to the New York Yankees for a player to be named. Ryan lost his starting job to Brad Miller shortly after the rookie was called up from Triple-A Tacoma on June 28.