Brendan Fraser Surprises Whisky a Go Go Crowd, Supports Son After Oscars Win

Brendan Fraser‘s Oscars celebration is now a full-fledged family affair … after his fun night at a legendary Sunset Strip club where his son hopped onstage to jam out.

TMZ obtained video of Brendan and his son, Leland, having a ball Monday night at Whisky a Go Go in WeHo … chilling in the green room and signing the performer’s wall.

Brendan takes a few beats to find the perfect space to leave his John Hancock, with onlookers making a wisecrack about his handwriting … and then Leland follows suit, and gets an earful too.

Folks who were there tell us Brendan and his son got to the venue around 9 PM and watched an ’80s cover band perform … with Leland even jumping on the stage to play guitar with the band at one point.

Leland’s dad was a big hit at the Whisky, as tons of people came up to his table to congratulate him 24 hours after his Academy Award victory … and we’re told he didn’t turn away anyone. Folks who met Brendan described him as very down-to-earth.