SAN FRANCISCO -- Austin Slater and Thairo Estrada were initially slated to bat first and second for the Giants on Friday night, but the pair ended up being scratched less than an hour before first pitch with dizziness and conjunctivitis, respectively.

In stepped Luis Matos and Wilmer Flores, who combined to go 6-for-8 with three RBIs at the top of the lineup to spark the Giants’ wild 9-8 comeback win over the last-place Rockies at Oracle Park.

• Games remaining (21): vs. COL (2), vs. CLE (3), at COL (4), at AZ (2), at LAD (4), vs. SD (3), vs. LAD (3)
• Standings update: The Giants (71-70) are 2 1/2 games behind the D-backs (74-68) for the third and final National League Wild Card spot. They also trail the Marlins and Reds in the race.

Flores cranked the first of three consecutive home runs off left-hander Ty Blach to help San Francisco erase a four-run deficit in the sixth inning and then drew a bases-loaded walk off reliever Evan Justice to force in the go-ahead run in the eighth and collect his 500th career RBI.

The Giants broke out for 13 hits, including four homers, to overcome deficits of 4-0 and 7-4 and snap their season-high-matching six-game losing streak. It marked the first time San Francisco had scored at least nine runs since July 18 at Cincinnati.  

“When you go down in a game several times and we’ve had some of the challenges that we’ve had in the last month, it’s pretty easy to pack it in in those games,” manager Gabe Kapler said. “These guys are nothing else if not fighters. I’m really proud of the at-bats and the continued effort all the way through this game.”

The Giants entered Friday winless in September following a dismal 1-6 road trip to San Diego and Chicago, and they appeared in line to continue their downward trend after falling behind early against the cellar-dwelling Rockies.

Third baseman J.D. Davis committed an error that ignited Colorado’s three-run second inning against prized left-hander Kyle Harrison, and Matos was easily thrown out at home by center fielder Nolan Jones following an aggressive send by third-base coach Mark Hallberg in the third.

The Giants were blanked through the first five innings by Blach, who spent his first four Major League seasons in San Francisco, but they finally broke through in the sixth thanks to Flores, who blasted a two-run shot out to left field to cut the deficit to 4-2. Mitch Haniger followed with another homer -- his first since May 27 -- to bring the Giants within one, and Davis completed the trifecta with a game-tying drive that landed halfway up the left-field bleachers. It was the first time the Giants had gone back-to-back-to-back since Denard Span, Joe Panik and Buster Posey accomplished the feat on April 4, 2016, at Milwaukee.

“That was unbelievable,” said Harrison, who gave up four runs (three earned) over five-plus innings in his fourth career Major League start. “I couldn’t believe it. It was great. We needed that.”

Colorado quickly regained the lead on Elias Díaz’s three-run blast off left-hander Taylor Rogers in the seventh, but the Giants pulled within one on Blake Sabol’s two-run shot in the bottom half of the inning. Matos nearly tied it up again by sending a deep drive to center field, but he had to settle for a double after it hit off the top of the wall.

Matos, who finished 3-for-4 with a walk in his first game out of the leadoff spot, thought it was gone off the bat and tried to high-five Giants first-base coach Antoan Richardson as he rounded the bag, but Richardson pulled back once he saw the ball stay in the yard.

“The emotion of the game got to me,” Matos said in Spanish. “I thought it was gone, but I still got the double.”

Matos was left stranded after Jake Bird retired Flores, pinch-hitter LaMonte Wade Jr. and Davis to end the inning, but he came up in another big spot during the Giants’ decisive rally in the eighth. After Mike Yastrzemski tied the game with an RBI single to right field, Matos stepped up with the bases loaded and one out, though he struck out looking on a 2-2 fastball from Justice that appeared to be off the plate.

“I thought Matos’ at-bats were sensational today,” Kapler said. “Even in his last at-bat, I felt like he was going to win that one.”

Still, the Giants managed to complete their comeback with back-to-back walks from Flores and Wade. They turned a two-run lead over to closer Camilo Doval, who gave up a two-out RBI double to Jones in the top of the ninth before striking out Brendan Rodgers to end the game.