NEW YORK—Bernard Tomic has been fined $10,000 by the International Tennis Federation for unsportsmanlike conduct during the first round of the U.S. Open.

The Australian's vulgar comments to a spectator were heard on camera during the first set of his loss to Damir Dzumhur.

Tomic said the spectator was "baiting" him, though he did apologize after the match.

"He was, for sure, in the moment saying a lot of stuff to me,” Tomic said. “But it's OK. It's just sometimes the crowd [needs] to be respectful, especially at a big major."