Heartache might have hit Miley Cyrus like a wrecking ball, but it appears as if fiance Liam Hemsworth is handling their rumored breakup just fine.

Or maybe the Aussie actor simply needed a night out with the guys. And where better than the City of Sin? Like many other celebs, including Justin Bieber and Lil Wayne, Liam hit Las Vegas for the big Floyd Mayweather vs. Canelo Alvarez fight on Friday (Sept. 13).

As news broke that Miley and her family unfollowed him on Twitter, Hemsworth appeared in "good spirits" at a VIP pre-party for the bout, a source tells E! News. The 'Hunger Games' hunk arrived at the bash with a group of guys and 'Twilight' actress Ashley Greene. Keep in mind, Smilers, that no one is whispering -- yet, anyway -- that the movie stars are now dating each other.

Hemsworth spent only a half hour at the bash, but the source reports he "seemed really chill and in good spirits," sipping a beer and posing for fans' photos. "He was just hanging out with his friends," the source continues. "It was a guys' weekend in Vegas."

Breakup rumors have dogged Miley and Liam for months, with insiders saying the couple is close to calling off their rocky relationship for good. There is not a person in the world who would be surprised.

A chill Hemsworth greets a friend ringside in Vegas.

Bryan Steffy, Getty Images