By Scott Tady

BURGETTSTOWN — Avril Lavigne plus the words “greatest hits tour” equaled a jam-packed Pavilion at Star Lake on Thursday.

Canada’s pop-punk princess showcased hits, including set-starter “Girlfriend” with its leadoff line “Hey, hey, you, you, I don’t like your girlfriend,” setting a tone for breezy, sing-along fun.

The sound could have been better — it was over-amplified and muffled for much of Lavigne’s banter — but the hooks rang true, as on fan favorites “Complicated” and “My Happy Ending” featured in the first-third of the performance.

Lavigne charmed fans with her enthusiasm, sincerity and spunkiness. She pantomimed a punch with a P-popping vocal sound to punctuate one of the more rousing “Complicated” moments.

“Here’s to Never Growing Up” tracked philosophically with the decisively girls-just-want-to-have-fun crowd.

For “Keep Holding On,” Lavigne grabbed an electric guitar, joining forces with her band’s two six-stringers.

Having earlier sung a faithful cover of The Chicks’ “Wide Open Spaces,” a seated Lavigne started out acoustically on “Breakaway,” a song she wrote as a 16-year-old that became a smash hit for Kelly Clarkson.

Thanking fans for their decades of support, Lavigne noted this was a greatest hits tour, but she couldn’t resist gathering with opening act Simple Plan before hitting the road months ago to record a new, nostalgia-driven song, “Young & Dumb.” Simple Plan singer Pierre Bouvier came out on stage so they could perform it live. A half-dozen, randomly chosen, ardent young fans were brought onto the stage for visual accompaniment. Lavigne handed each of those fans an autographed skateboard while Pierre tossed bundled up concert T-shirts into the crowd.

From those joyful and sweet moments, Lavigne somehow segued into “Bite Me.”

Back to her skateboard roots she went for “Sk8er Boi,” another jubilant singalong that got spectators dancing.

By that point, a heavy rain was falling, but the mood was never dampened for fans who got to witness the 40-year Lavigne in maybe her biggest ever western Pennsylvania headlining visit.

Simple Plan set the stage well for her, with a blissful, boisterous pop-punk set. Bouvier introduced “I’m Just a Kid” as a song written 23 years ago, acknowledging that would make some fans shout “(heck) yeah!” and make others put their head in their hands and groan “oh (heck) no.” Wearing a T-shirt that said “I’m Just a Kid” with the “kid” crossed out and replaced by the word “adult,” Bouvier engagingly commanded the stage, taking a turn behind the drum kit as drummer Chuck Comeau ran through the crowd slapping high-fives.

The Montreal mirth-makers maintained an entertaining, upbeat vibe.