Prior to the game at Chicago's Wrigley Field, according to the Associated Press, Rizzo met a nine-year-old boy named Matteo Lambert in the dugout. Lambert asked Rizzo to hit a "moonshot" in support of Lambert's group, which is running a 5K race in Chicago's Grant Park to raise money for children with cancer.
"That was for him," Rizzo said of his grand slam, referencing Lambert.
Rizzo was diagnosed with Hogdkin's lymphoma at 18 years old in 2008 and went into remission the same year. He has since founded the Anthony Rizzo Family Foundation, whose mission "is to raise money for cancer research and to provide support to children and their families battling the disease."