SAN FRANCISCO -- The San Francisco Giants leaned on their youth movement Tuesday night, with rookies Bryce Eldridge and Carson Whisenhunt delivering the key performances in a 4-1 victory over the Houston Astros at Oracle Park.

Whisenhunt, making his sixth start of the season, faced immediate trouble. In the first inning, he hit Astros second baseman Jose Altuve with a pitch, loading the bases with one out. But the 24-year-old left-hander bore down, getting Christian Walker to pop out to short right field and Nelson Velázquez to ground out to third base in his first at-bat for Houston after being claimed off waivers from St. Louis. The Astros loaded the bases again in the second inning, this time with no outs, after a walk and two singles. Yordan Alvarez lifted a sacrifice fly to center field, giving Houston a 1-0 lead, but Whisenhunt escaped further damage by inducing a groundout and a flyout.

Altuve, who stayed in the game after being hit, did not return for the bottom of the second. The team later announced he had a left foot contusion, raising questions about his availability for the series finale.

The Giants tied the game in the bottom of the second. Rafael Devers drew a walk from Astros starter Hunter Brown and moved to second on a wild pitch. Drew Gilbert then lined a single to left field, scoring Devers. In the fourth inning, Gilbert worked a walk after a successful ABS challenge, advanced to second on a groundout, and came home on a single by rookie Drew Cavanaugh.

Eldridge, the Giants' first-round pick in 2023, provided the power stroke in the fifth. He crushed a 1-0 pitch from Brown over the fence for his 12th home run of the season, pushing the lead to 3-1. The rookie first baseman finished 1-for-4.

San Francisco added insurance in the sixth. Cavanaugh singled off reliever Enyel De Los Santos, and rookie Christian Koss doubled to left-center, plating Cavanaugh for a 4-1 advantage.

Whisenhunt settled impressively after the early struggles. He retired 11 consecutive batters at one point, mixing a low-90s fastball with a deceptive changeup. He departed after a two-out walk in the sixth, matching his longest outing of the season at 5 2/3 innings. He threw 96 pitches, with 55 coming in the first two frames. The line: one run, four hits, three walks, and three strikeouts, improving to 3-3.

Carson Seymour took over and pitched two scoreless innings, allowing just one hit. Reiver Sanmartin recorded the final out of the eighth, and JT Brubaker worked a clean ninth inning for his second career save.

Brown, the Astros starter, went five innings, surrendering three runs on five hits and three walks, falling to 3-2. Houston's bullpen held the Giants scoreless after the sixth, but the offense could not mount a comeback.

Houston dropped to 61-60, while the Giants improved to 50-70. The teams split the first two games of this three-game series, with Houston winning Monday's opener 6-3 in 10 innings. Neither team has announced a starting pitcher for Wednesday's finale.