Playing right field, Williamson charged Mark Teixeira's fourth-inning single too hard and overran the ball for an error. That enabled Didi Gregorius to score the afternoon's first run -- which seemed like 10 runs, given the Giants' .239 batting average during their six-game losing streak.
That misplay actually wasn't Williamson's first shaky moment of the game. He was thrown out at home plate while trying to score from first base on Ramiro Pena's third-inning double. However, Williamson remained calm after committing his error and reminded himself, "There's plenty of opportunity left to make an impact." In fact, Williamson's power potential and recent run-producing surge largely explained his presence in the Giants' lineup.
Williamson rewarded manager Bruce Bochy's faith by homering in the fifth inning and driving in the go-ahead run in the 12th. His was a redemptive performance, blending neatly with the end of the Giants' six-game losing streak.
Said Bochy, "What I like about what happened, Mac made the error and lets in a run. He put that behind him, he didn't let it bother him and he hits a home run. You have to be resilient in this game and he did a good job of it."
Each time Williamson's gaze strayed toward the pitcher's mound when the Giants batted, he received a vivid reminder of the adversity he has weathered. There stood Yankees starter Ivan Nova, who underwent Tommy John elbow surgery the same day Williamson did -- April 28, 2014, performed by noted orthopedist Dr. James Andrews.
"Fun fact," Williamson said.
As a rookie, Williamson hasn't had time to develop an overwhelming reputation, though skeptics have identified him as a right-handed batter who struggles against right-handed pitching. He entered Saturday batting .222 (6-for-27) with a .370 slugging percentage and one home run against right-handers this season, compared with .245 (12-for-49) and a .531 slugging percentage with four homers off lefties.
However, Williamson delivered his pair of big hits in this game off right-handers.
The 26-year-old won't let himself be defined by what others believe he can or cannot do. Listening to wisdom from more experienced teammates has fortified him, especially as he endured four callups and demotions between San Francisco and Triple-A Sacramento.
Williamson spoke of an inspirational chat he had in St. Louis with catcher Buster Posey. And right-hander Jake Peavy has invited Williamson to share his in-season residence with him. That has meant gleaning shreds of knowledge from Peavy's 14 Major League seasons during their leisure time.
"They've been great mentors to me," Williamson said.
Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.