SF Giants lose 5-3 after Ketel Marte walkoff home run in four-run 9th inning

PHOENIX, ARIZONA - MAY 19: Ketel Marte #4 of the Arizona Diamondbacks reacts after hitting a walk off three-run home run against the San Francisco Giants during the ninth inning of the MLB game at Chase Field on May 19, 2026 in Phoenix, Arizona. The Diamondbacks defeated the Giants 5-3. (Photo by Christian Petersen/Getty Images) | Getty Images There’s an old sketch from The State called “The Barry Lutz Show” where a doctor played by Thomas Lennon explains his research in the field of “monkey torture,” accompanied by an adorable simian.

He eventually takes a phone call that purportedly tells him he has to stop torturing monkeys forever and let them all go, only to reveal it was just his friend Terry making a prank call — an even more sophisticated bit of monkey torture. The San Francisco Giants spent most of Tuesday’s game with the Arizona Diamondbacks clinging to a two-run lead, escaping bases-loaded situations in the 7th and 8th inning with double plays. But the lack of insurance runs and an unreliable bullpen killed them when Ketel Marte hit a two-out, three-run home run off Matt Gage to give the D-Backs a 5-3 win.

Marte Madness 🤯 pic. twitter. com/wMvhoy7BMC — Arizona Diamondbacks (@Dbacks) May 20, 2026 At least it wasn’t Nolan Arenado that beat them this time.

Is it worse to lose by 12-2 in a game that’s never close or have hope for 26 outs, only to have defeat snatched from the jaws of victory? The 2026 Giants can offer both forms of monkey torture. The Giants wasted a solid Landen Roupp start, stellar infield defense, and back-to-back jacks from Rafael Devers and Willy Adames after a nightmare four-run 9th.