SAN FRANCISCO — Marlon Byrd said there was only one way he could have enjoyed his 38th birthday more.
"Yeah, with a 'W,'" he said.
"He kept getting us back into the game every at-bat," Giants manager Bruce Bochy said. "What a great job he's done for us."
Byrd's only out was a sinking liner that Brandon Moss dove to catch, stranding two runners in the third.
Byrd doubled twice, both to right field, and tripled as the Giants' 3-4-5 hitters were a collective 10 for 12 and scored all five runs. Nori Aoki collected the other two hits while the rest of the lineup went hitless in 21 at-bats.
"We swung the bats well," Bochy said. "It was just too big of an uphill climb."
Heston (11-8) returned to the rotation for the first time in two weeks. He was optioned to Triple-A Sacramento but did not pitch in a game, instead throwing two bullpen sessions.
"I don't think that affected me," Heston said. "I felt fresh. I just got some balls up and they hit them hard."
Heston gave up five runs on nine hits in his 3 2-3 innings of work. He did not walk a batter and struck out one, matching his season low.
"They got him early. He didn't get a chance to settle in," Bochy said. "He was off. Too many mistakes got him. He wasn't as sharp as he usually is."
Kelby Tomlinson also drove in a run for the Giants, who ended a 3-3 homestand.
Brandon Belt had four hits and Buster Posey collected three hits for the Giants.
The Giants open a three-game series against the NL West-leading Dodgers in Los Angeles on Monday night.
"We're not where we want to be but we're in the hunt," Bochy said. "This is a huge series for us. We're behind and I hope we go down there and get back on track."
The Giants have won nine of the first 12 meetings with their rivals, though they haven't met in more than two months.
"You look forward to a series like this, especially when you're behind," Bochy said. "We need to win ballgames. It's that simple."
Matt Carpenter hit the second pitch of the game for a home run as the first four Cardinals reached base safely. Stephen Piscotty singled, Heyward tripled and Molina singled.
"It was pretty quick. The first six pitches and they had a couple of runs and a runner at third," Heston said. "Before I knew it, it was getting ugly."
The Giants got two runs back in the first on Byrd's first double but the Cardinals tacked on runs in the third, fourth and sixth.
Byrd, who doubled in a run in the sixth and tripled in another in the eighth, has 11 RBIs in his last four games.
Giants: Infielders Brandon Crawford (tight oblique) and Joe Panik (lower back inflammation) both took grounders Sunday. Crawford is expected to play Monday night against the Dodgers.
Giants: RHP Jake Peavy (4-6, 4.21) gets the call Monday night against LHP Brett Anderson (8-8, 3.36) in Los Angeles.