NEW YORK -- Getting thrown out at the plate was frustrating, allowing a run to score on an error was disappointing and not being able to get the go-ahead run in from second base was a downer.

Hitting a home run was nice, but getting the game-winning hit was even better.

All of those happened to Mac Williamson on Saturday.

Eventually, the unsuccessful plays were forgotten when Williamson capped his eventful day by getting the tiebreaking single with one out in the top of the 12th inning and the San Francisco Giants ended a season-high six-game losing streak with a 2-1 victory over the New York Yankees.

Williamson was involved in many facets of the four-hour, 25-minute marathon. He was thrown out at the plate in the second trying to score from first, committed an error in right field on Mark Teixeira's single, allowing the Yankees to score.

An inning later, he shook off the error by hitting a home run off Ivan Nova and creating a deadlock that lasted nearly another three hours.

Williamson prolonged things when he struck out against Aroldis Chapman for the first out of the 10th with Grant Green standing on first.

"(I had) plenty of opportunity to make an impact, that's all I was trying to do," Williamson said.

Finally, much to the delight of the many orange-clad Giants fans, Williamson came through, slicing a 1-and-0 slider from Anthony Swarzak (1-1) up the middle.

The ball eluded shortstop Didi Gregorius and Trevor Brown easily scored from second, giving the Giants their first lead of the series.

"I just was looking for something up over the plate," Williamson said. "I faced Chapman there in the 10th after Grant had led off with a double and couldn't get him over, couldn't get him in.

"That was frustrating and then kind of the same exact opportunity at that point."

It was Williamson's third big hit in less than 24 hours. On Friday, he had the game-tying double off Andrew Miller in the eighth, when he got the hit on a full count and fell behind 0-and-2.

The Giants won for the first time in nearly two weeks even though Angel Pagan stayed at third when Dellin Betances' first pitch to Brandon Crawford went over catcher Brian McCann's head and to the backstop.

After the unsuccessful intentional walk ended, the Yankees pitcher to Crawford and the inning ended with a groundout.

San Francisco also ended its skid after Santiago Casilla (2-4) worked out of a bases-loaded jam in the 10th. He created it by intentionally walking Carlos Beltran following a sacrifice bunt by Jacoby Ellsbury and ended it by getting fly balls by McCann and Starlin Castro.

Appropriately enough, Castro's fly ball down the right field line required Williamson to lean into the stands to maintain possession.

Casilla was one of six relievers who combined to allow three hits in six scoreless innings.

When Hunter Strickland retired Beltran for the final out of his second save, many of the San Francisco fans gave the team a loud ovation as the players headed off the field.

"The 'pen stepped up," Giants manager Bruce Bochy said. "These guys did a good, terrific job of picking each other up."

While the Giants were 1-for-11 with runners in scoring position and struck out 13 times, the Yankees were not much better. New York (49-48) went hitless in 10 at-bats with runners in scoring position and struck out 12 times in its longest game of the season.

"It hurts because we had opportunities to score some runs and we weren't able to do it," Yankees manager Joe Girardi said. "To lose a game 2-1 in 12 innings is really difficult."

Before the marathon ended, both starters settled down after an eventful four innings.

San Francisco's Johnny Cueto allowed one run and six hits in six innings while throwing 117 pitches. Cueto struck out nine, including six of the last eight hitters he faced.

New York's Ivan Nova matched Cueto and went an inning further. He retired the last nine hitters he faced and 12 of the last 13.

The teams had plenty of opportunities in the first five innings, putting a combined 14 runners on.

NOTES: San Francisco manager Bruce Bochy said the team intended to start RHP Johnny Cueto all along but there was a miscommunication. "That's been done," Bochy said. "There was a little confusion on that. We thought we had done it. This wasn't done last night which a lot of people think." ... Yankees 1B Mark Teixeira batted seventh for the first time since May 21-22, 2012, against the Kansas City Royals. ... San Francisco 2B Joe Panik (concussion) was checked out by team doctors and there were not any physical issues. He will do baseball activities on the side and will not play in a game with Triple-A Sacramento for another few days. ... Cueto said he was expecting to visit the White House this week with the Kansas City Royals but never heard from anyone with the team. ... Giants RF Hunter Pence (hamstring) will play six innings for Triple-A Sacramento on Saturday and seven on Sunday. ... From the fun fact department: San Francisco RF Mac Williamson and New York RHP Ivan Nova had their Tommy John surgeries performed on the same day on April 28, 2014.