David Ortiz was on first base in the fifth inning Thursday night when Mike Carp drove a single into center field.

Ortiz, running hard with two outs, hit second base and headed for third. The crowd at Fenway Park cheered like they were watching the 100-meter final at the Olympics.

As for the Red Sox dugout, “Everyone was screaming and yelling,” starting pitcher Clay Buchholz said after a 7-2 victory against the Houston Astros.

Going first to third on a two-out single is routine for most players. But not for a 37-year-old, 230-pound designated hitter who started the season on the disabled list recovering from a strained right Achilles’ tendon.

“We need David and seeing him play like that had everybody smiling,” Buchholz said. “It’s huge for our team.”

Ortiz was 3 for 4 with his first home run of the year, two runs batted in, and three runs in support of Buchholz. He is 11 of 20 with four extra-base hits and five RBIs in five games since being activated.

“It’s remarkable the timing that he’s displayed, particularly after the layoff that he’s had,” manager John Farrell said. “Even guys in the dugout are kind of marveling at what he’s been able to do. Not only contact, but driving the baseball.”

Ortiz didn’t play any games in spring training. His only preparation was six games and 18 at-bats with Triple A Pawtucket.

“I’ve been working to stay short and quick to the ball. Not try to do too much,” Ortiz said. “I always tell you guys, I’m old enough to know what it takes to be what I want to be.”

Ortiz’s home run was a booming shot to straightaway center field in the third inning off Houston starter Philip Humber. The ball landed several rows back, an impressive poke on an April night. Usually you don’t see that kind of carry at Fenway until the summer months.

“Crushed it,” said Ortiz, who has a 17-game hitting streak dating to last July.

But the best aspect of the game for Ortiz was how well he moved on the bases. In addition to his journey in the fifth inning, he scored from second on a single in the first.

If the 15-7 Red Sox are to contend into the heart of the season, a healthy Ortiz is a necessity. Thursday was the first time he ran without any apparent hesitation.

“It feels good. Those are the kind of tests that I’ve got to go through and get used to,” Ortiz said. “Once I do that, I get more comfortable and my mind realizes that I have to continue doing things like that.”