Marin Cilic turned 30 years old on Friday, leaving Dominic Thiem as the only men's Grand Slam finalist from either this year or last to be in his 20s.

In celebration of the milestone, Cilic borrowed an idea from Jimmy Fallon and asked his followers on Twitter to do random acts of kindness and consider it his birthday gift.

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Fans came through and shared their stories in the replies:

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The Croatian also celebrated with a team dinner in Tokyo, where the Rakuten Japan Open Tennis Championships begin on Monday.

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The world No. 6 has a big fall season ahead of him, with Croatia in the Davis Cup final, and his own qualification for the ATP Finals looking very likely.