HOUSTON -- On the day the Astros welcomed slugger Kyle Tucker back to their lineup for the first time in three months, Yordan Alvarez reminded everyone he was here all along.

Alvarez swatted a pair of three-run home runs for his franchise-record-tying seventh multihomer game of the season, while Framber Valdez held the high-scoring Diamondbacks scoreless for seven innings in the Astros’ 8-0 win on Friday night at Minute Maid Park.

"Very happy that he’s back,” Alvarez said regarding Tucker. “Obviously, the team, the city, everybody was waiting anxiously for him to come back and I think it's a big relief for him to come back in the lineup."

The Astros, coming off a three-game sweep at the hands of the Reds in Cincinnati, won their fifth consecutive game at home and remained 4 1/2 games ahead of the second-place Mariners in the American League West, with 21 games remaining.

Tucker went 0-for-2 in his first game since June 3 -- he fractured his right shin on a foul ball that night -- but drew a walk and reached base in the first inning when he was hit by a pitch.

"[With] Kyle being in the lineup, I thought there was a little bit of extra energy in the clubhouse today,” Astros manager Joe Espada said. “The guys were really excited, especially after not playing well in Cincinnati. I thought that we came out ready to go. I thought Tucker kind of helped out. The guys were excited about that and we felt complete today. Getting him back on the field and getting the fans excited about Kyle Tucker being there, that was important.”

Alvarez homered into the upper deck in right field in the fifth inning off Arizona starter Brandon Pfaadt and homered into the Houston bullpen in right-center off reliever Jordan Montgomery in the sixth. He joined Chris Carter (2014) as the only two players in franchise history with seven multihomer games in a season.

"Framber navigated that lineup very nicely, and that sets up our offense,” Espada said. “Yordan ... it’s not that easy, y’all. This guy is so good in how he makes it look. Tucker’s at-bats were pretty good. He saw a ton of pitches and I thought that was really good. The bottom of our order had some men on base and allowed [Jose] Altuve and Yordan to come up with people on base. Really good team win.”

Alvarez had gone 105 plate appearances without a home run at Minute Maid Park before hitting a pair of homers on Sunday against the Royals, which was Houston’s most recent home game prior to Friday. Thus, Alvarez has four homers in his last two games at home after hitting no homers with only five RBIs in his previous 25 home games (June 23-Aug. 31).

"Alvarez is doing it at a high level,” D-backs manager Torey Lovullo said. “There's no mysteries. He's a very powerful hitter. He's a very smart hitter. We just made some mistakes. We went to certain spots too many times, and we suffered the consequences."

Valdez (14-6) won for the ninth time in his last 10 decisions by holding Arizona, which entered the day leading the Major Leagues in runs scored, to two hits and three walks while striking out seven batters. He lowered his ERA to 2.97 in 157 1/3 innings.

"It’s also part of my job to try to get the team out of a hole,” Valdez said. “It’s very important, obviously, to try to come back tomorrow and continue playing well and win."

Valdez is having one of the best stretches of his career. He’s 9-2 with a 2.21 ERA and 1.00 WHIP in 89 2/3 innings in 14 starts since June 18. The Astros have gone 12-2 in those starts, as Houston has gone from a 10-game division deficit to 4 1/2 -game lead in that span.

"I think there is a method to what he does,” Lovullo said. “He's very confident stepping off the mound then stepping up there quickly to get into his motion because of the pitch timer. He's in total control. He's controlling the climate of what's happening, and when he was making pitches, we just couldn't get into a rhythm with him."