Joe Manganiello partied sans girlfriend Sofia Vergara at a fashion event in Los Angeles on Tuesday night, but that didn't mean the "True Blood" hunk wasn't thinking about her.

Manganiello was overheard saying this "has been his best year yet."

"He was really happy, upbeat," said a witness at the James Jeans and New Balance party.

At the soiree, Manganiello, 37, danced and chatted with fellow celebrity guests, including Minka Kelly and Mandy Moore.

Manganiello and the "Modern Family" star, 42, have been going strong since earlier this summer.

One source told us last month that it "wouldn't be" surprising "if things got serious really quickly" between the two.