TORONTO -- She's just launched her first headlining North American tour -- last night at the Air Canada Centre -- and Avril Lavigne has already figured out how to make her breakthrough song, Complicated, interesting: Drag two fans from the audience on stage with her to sing some of the verses.

In the case of last night, it was a 12-year-old girl and a tall and strapping boy -- I didn't catch his age -- who were given the honours. The girl, in particular, did rather well in the spotlight as she belted out the words while dressed in a souvenir "Avril" toque.

As for Lavigne herself, the teenaged pop-rock sensation seemed quite comfortable as well, having just returned from a European headlining tour.

She began the hour-and-five-minute show with the punk-pop anthem Sk8ter Boi, the second single off her breakthrough debut album, Let Go.

Perched on a tiny ramp on an otherwise stripped-down stage, the 18-year-old from Napanee, Ont., quickly ran toward the front and hundreds of screaming, mainly young, female fans -- many with their mothers and fathers -- who were already chanting "Avril! Avril!" before the lights even went down.

"It's good to be back in Canada," screamed Lavigne, backed by a three-piece band including a shirt-less drummer. "This is our first show on our North American tour, so we're quite excited."

The Toronto kick-off of the Try To Shut Me Up Tour sold out in about 10 minutes after tickets went on sale back in late January.

So the crowd of 16,000 fans had some time to let the anticipation for Lavigne's visit build.

As it was, they enthusiastically sang along to her biggest hits -- the aforementioned Complicated and Sk8ter Boi and I'm With You.

The singer, meanwhile, was fresh off winning a leading four Juno trophies -- second only to host Shania Twain's three wins -- this past weekend in Ottawa at the Corel Centre. (She returns to the scene of the Juno Awards tonight to play a show.)

While in the nation's capital, she also had an audience with the prime minister himself, who presented Lavigne with the diamond award for album sales of one million in Canada.

The challenge right now would appear to be having enough material to stage a lengthy concert. As it stands, she only has the 13 songs from her debut and the odd b-side and cover (Green Day's Basketcase) to sustain her, which is probably why the show felt like it ended just as things were really getting going.

Avirl's stage antics included twirling on one spot during Sk8ter Boi, riding the shoulders of a security guard in the front section of the crowd during Nobody's Fool, strapping on an electric guitar for songs like Mobile and Naked or jumping on spot during In My World. Otherwise, Lavigne recalled a young Alanis Morissette at times with her big voice and long hair hanging in her face.

When she returned for the encore, Lavigne was joined by her guitarist on acoustic guitars for a stripped-down rendition of Tomorrow. But the entire band eventually returned for a plugged-in version of Things I'll Never Say, the last song of the night. (More on Avril Lavigne)

JAM! Rating: 3 out of 5