Bryce Harper and the Philadelphia Phillies took on the Chicago Cubs in August during the 2019 season. Chicago quickly had Philadelphia's back against the wall, getting out to a 5-0 lead by the fifth inning.
However, the Phils would start to claw their way back in the eighth with a run. They then scored two more runs and loaded the bases up for Harper in the ninth inning.

He proceeded to crush a second-deck walkoff grand slam home run. It was a remarkable moment, but it was one that both his mother and father missed, as they called their night early, via CBS.
"I saw my parents' lights are off in the suite right now, so they probably didn't see that, so thanks mom and dad, appreciate you," said Harper.
Harper jokingly held a grudge against his parents for missing such a remarkable moment. Harper was then asked what went on in his mind during that at-bat, where he stated he was sitting on one pitch.
"I was really trying to get a sinker that he missed over the plate, and I kind of cheated on that one right there," he added.
It was a great comeback win by the Phillies. While many teams would have folded down a handful of runs early, Philadelphia bit down on their mouthpieces and went to work.
Bryce Harper watched his former club win the World Series that year

During the 2010 MLB Draft, the Washington Nationals selected Bryce Harper with the first overall pick. He would go on to stay with the club until 2018, and after that, he became a free agent.
Washington tried to reach an extension, but that failed. They then tried to re-sign him as a free agent, but he chose to sign a 13-year, $330 million contract with the Phillies.
While losing their young star, the Nationals played well that year. They finished second in the National League West, right behind the Atlanta Braves. It was good enough to secure a postseason spot.
Washington put away the Milwaukee Brewers and then the Los Angeles Dodgers in the NLDS. They then took on the St. Louis Cardinals, sweeping them 4-0 to make it to the World Series.
In the World Series, they were able to defeat the Houston Astros in an exciting series. It went the distance, going seven games to decide the winner, and all Harper could do was watch from home.