PHOENIX — How can you not be romantic about baseball? Brad Pitt's character in the film "Moneyball" poses that very question and points out incredible moments to support his point.

And if his character heard the recent story of Alex Robertson and his experience at Tuesday's Arizona Diamondbacks game, he'd certainly add it to his argument. 

Robertson's story began to take off online after he posted a tweet after the D-backs' game against the Texas Rangers. In the tweet, he says he was the fan who caught the walk-off home run ball hit by center fielder Jarrod Dyson. But the ball is more than just a piece of memorabilia.

RELATED: Huge hot dogs lead off home-run hitting lineup of new menu items at Chase Field

According to the tweet, Robertson's father recently died in March and baseball was his favorite sport. And on Robertson's 21st birthday, he caught the home run ball.

"This one's for you pops," Robertson wrote in the tweet.

The post quickly went viral, receiving more than 8,000 likes. People are also sharing their condolences to Robertson online and expressing their appreciation for him sharing the touching moment.

During an interview with 12 News, Robertson said his dad was his best friend and they bonded by watching baseball games together. Alex’s 21st birthday was three weeks to the day from when his dad passed away.

The D-backs have the ball and said the team would send it to him signed by Dyson. Robertson said he plans on putting it next to his dad’s ashes.

It's a moment that baseball fans across the world are connecting to and is another incredible example of just how poignant and powerful sports can be.