CHICAGO — The Giants looked headed for disaster. They ended up with a testament to their collective resilience.

The Giants scored a shocking nine runs in the top of the 11th inning after Ryan Walker blew a save in the bottom of the ninth inning, stunning the Chicago Cubs to win 14-5 on Tuesday night at Wrigley Field.

Kyle Harrison made his debut as a reliever in the bottom of the 11th inning, pitching a scoreless inning to slam the door on the Cubs.

In the top of the 11th, San Francisco delivered one heck of a haymaker after Chicago tied the game in the bottom of the ninth. Patrick Bailey drove in the go-ahead run with an RBI single, giving the Giants a 6-5 lead. And they were just getting started.

San Francisco followed up by executing a rare squeeze play; Brett Wisely laid down a bunt, and Heliot Ramos beat the throw home to expand the lead to 7-5.

It continued to snowball from there.

Willy Adames was hit by a pitch with the bases loaded. Jung Hoo Lee drove in a run with a bases-loaded single. Matt Chapman followed with a two-run single. Wilmer Flores had an RBI single. Cubs reliever Ryan Pressly exited the ballgame without recording a single out.

Against Caleb Thielbar, the Giants kept adding on. Heliot Ramos knocked in a run with a loud double, and Bailey drove in another run with a sacrifice fly. By the time Thielbar recorded the third out, Pressly was charged with nine runs and more than half the home crowd headed for the exits.

That nine-run 11th inning helped erase the memory of a disastrous ninth inning.

Walker began his night by walking the speedy Pete Crow-Armstrong in the ninth, bringing the tying run to the plate with no outs. The right-hander struck out Dansby Swanson but walked Carson Kelly and allowed an RBI single to Justin Turner, shrinking the Giants’ lead to 5-4.

Walker struck out Ian Happ for the second out, but instead of leaving in his closer, manager Bob Melvin elected to summon left-hander Erik Miller to face left-handed batter Kyle Tucker — one of baseball’s best hitters. The decision didn’t pay off.

Tucker smashed a single into center field off Miller to drive in the tying run and make it 5-5. Miller struck out Seiya Suzuki to end the inning and send the game into extras, but screamed into his glove in frustration as he walked off the field.

The Giants couldn’t score the go-ahead run in the top of the 10th inning, but neither could the Cubs in the bottom half. To the 11th inning the ballgame went.

Justin Verlander, who allowed three earned runs over five innings, was in line for the win before Walker blew the save. He has now gone eight starts without a win, the longest winless streak of his career.