PHILADELPHIA -- Luke Williams raced around the bases.

His mind tried to keep up.

How could he possibly comprehend what happened to him in the ninth inning on Wednesday night at Citizens Bank Park? How could he possibly absorb everything that happened to him in the past week? Williams hit a two-out, walk-off home run to left field in a 2-1 victory over the Braves to become the first player in Phillies history to hit a walk-off home run in his first big league start.

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“I don’t know if I’ll have words to describe that moment,” Williams said. “It was pretty incredible, you know? I’m still trying to figure it all out.”

It capped an incredible week. Williams helped Team USA qualify for the Olympics on Saturday. He got called to the big leagues on Monday. He got a hit in his first big league at-bat on Tuesday. He got his first extra-base hit with a double in the fourth inning on Wednesday.

“It just adds to this whole journey,” the Phillies' No. 29 prospect said. “It definitely hasn’t been the easiest journey, but this is pretty awesome.”

The Phillies had not gotten a hit since Williams’ one-out double in the fourth. Andrew McCutchen worked a one-out walk in the ninth. Pinch-hitter Brad Miller popped out for the second out, which sent Williams to the plate.

Phillies right-hander Zach Eflin and a few others watched from the TVs in the trainer’s room inside the clubhouse.

“We were like, ‘He’s going to do it right here. Captain America is going to end this right here,’” Eflin said.

Williams looked for an inside fastball from Braves closer Will Smith, but Smith threw him a first-pitch slider instead for a called strike.

Smith threw a second slider, but Williams jumped it. He ripped a line drive to left field. Teammates started to climb over the railing in the dugout before the ball cleared the fence. They mobbed him at home plate. They dumped a water cooler on him. Bryce Harper hugged him and told him that he felt something special was coming in that at-bat.

But then Williams saw his family on the field. His father Mark, his mother Jeannine, his sister Sami and his brother Ike each made their way to Philadelphia to watch him play. Williams’ parents were in Florida last weekend to watch him play for Team USA. They flew from Florida to California on Sunday. They jumped on the first flight from LAX to Philadelphia on Tuesday morning. Sami flew from Iowa. Ike flew from Utah. Williams’ oldest brother, Jake, was in Mexico. He could not make it in time.

“It’s pretty incredible to have them here and be able to witness it with me in person,” Williams said. “It’s pretty special. You just can’t make this up. It’s pretty incredible. Obviously wish [Jake] was here, but he’s supported me like crazy throughout this whole process.”

Williams had not checked his phone yet, but he expected more text messages than when the news broke on Tuesday that he had been promoted.

A lot of people helped Williams get to this point. There probably was a Little League coach or a high school coach or a travel team coach running around their house going nuts on Wednesday night in California.

“It’s going to be hard to get back to everyone, but I’ll find a way to get back to them,” he said. “It wasn’t just me who got here. I had a lot of people who helped me out. Family, friends, coaches. Just thinking about them and thinking about everything that my parents have done for me. It’s pretty awesome.”

Williams is the fourth Phillies player to hit a walk-off home run for his first home run and the first since David Doster on June 21, 1996. He is the first Phillies player to hit a walk-off home run with the Phillies trailing and down to their final out since Pat Burrell on May 2, 2008.

It was a historic moment for Williams, but it was a big moment for the Phillies, too.

It is no secret they have struggled. They certainly have not given fans much to cheer about. The Phillies announced 13,552 fans attended on Wednesday, which was the third-smallest crowd in Citizens Bank Park history when the ballpark has been open to full capacity. They had their smallest crowd (13,125) on Tuesday. Maybe this sparks something.

“We’re fired up,” Eflin said. “It could very easily be momentum shifting for the season.”

It would be something if a third-round pick from the 2015 Draft did it.

“Last night was great. Today was even better,” Phillies manager Joe Girardi said. “I don’t know what his encore is.”