Chris Evans took a break from saving the world as Captain America to surprise a young fan fighting his own tough battle against brain cancer.

Evans visited 9-year-old Kenny Botting, who has a brain tumor and resides at Christopher's Haven in Boston. Botting lives with his mother and sister at the residence center that provides a home away from home for children with cancer and their families while receiving treatment at Massachusetts General Hospital next door.

The "Avengers" star spent quality time with his No. 1 fan and brought a few gifts along, which he signed. The two played in Botting's pillow fort and Evans found himself prisoner at one point when Botting tied him to a chair.

Evans, who grew up in nearby Sudbury, Massachusetts, signed autographs and posed for pictures with other residents of Christopher's Haven. He also took a tour of the facility, which he will help raise money for at a special event on Jan. 3 at Fenway Park with Boston Red Sox manager John Farrell and other guests.

"It's their strength that gives me strength," the "Captain America" star told CBS 4 in Boston. "No matter what hurdles are in my life it's nothing compared to what these families go through, so any way I can bring a smile it's worth it."

Botting told CBS 4 he was "more than happy" about the visit and wanted to tell Evans "thanks for coming." The young boy's mother felt the same.

"It was so generous of Chris to come and spend time with us," Botting's mother said. "To see my son tie up Captain America, it's amazing."

Evans will reprise his Captain America role in "Avengers: Age of Ultron," opening in theaters on May 1.