By JANE STEVENSON -- Toronto Sun

TORONTO -- "Hello, hello, Toronto!" sang U2 frontman Bono, ad-libbing the opening of the song Vertigo as the Irish rockers kicked off the second leg of their North American tour last night at the Air Canada Centre.

And despite the energetic launch with an upbeat tune off their latest album, 2004's How To Dismantle An Atomic Bomb, the Dublin band wasted no time returning to the very beginning of their 25-year-plus career.

The second song of the night was a glorious rendition of I Will Follow, from their 1980 debut Boy that almost eclipsed their opener. That was no easy feat given Vertigo was aided by the presence of large red light panels that descended from their enormous lighting and sound rig -- which surrounded them like beaded curtains.

"Tonight is a rock 'n' roll festival," Bono told the crowd of 19,000 in reference to the current Toronto International Film Festival that's taken over the city.

If there was ever a band up for the job of making T.O. forget about all those A-list celebrities in town, it is the arena-friendly U2.

They sold out four shows at the ACC in a total of 45 minutes with the other concerts taking place tomorrow, Friday and Saturday nights.

Adding to the excitement was a large oval catwalk -- much like the heart-shaped catwalk from their last tour but bigger -- onto which all four band members ventured out at one point in the show for a closer look at the crowd of 19,000.

Bono, 45, even grabbed one excited young female fan out of the audience and gave her an extended hug during With Or Without You.

There was also a large video screen above U2 that was split-screened into four segments to feature each band member in black-and-white closeups.

The band, rounded out by guitarist the Edge, 44, bassist Adam Clayton, 45, and drummer Larry Mullen Jr., 43, arrived in Toronto early Friday to rehearse at the ACC.

"How are you doing, Toronto?" Bono asked. "It's been a handsome looking city over the last few days."

U2 actually started their Vertigo tour March 28 in San Diego. The band's last show before coming to Toronto was Aug. 14 in Lisbon, Portugal.

There was definitely some evidence of having had some time off.

Even though his heart was as big as that oval catwalk -- particularly during the emotional tribute to his father, Sometimes You Can't Make It On Your Own, and the peace-promoting Miss Sarajevo --Bono's vocals weren't always strong as witnessed by his weak version of With Or Without You.

And rearrangements of tunes, like Elevation into a slower version, didn't always work.

The Edge, Clayton and Mullen, however, sounded superb, particularly the guitarist on such standouts as I Will Follow, Beautiful Day, City Of Blinding Lights, Miracle Drug, Pride (In The Name Of Love), and Where The Streets Have No Name.

It was also cool when the Edge and Clayton switched instruments during the show-ending 40 or the Edge and Mullen played keyboards on Miss Sarajevo and Yaweh, respectively.

Crowd singalongs proved equally infectious on I Still Haven't Found What I'm Looking For, Sunday Bloody Sunday, Pride (In The Name Of Love), One and 40.

And Bono couldn't let the evening go on without applying more pressure on Canadian Prime Minister Paul Martin to cancel Third World debt.

"He's been improving," Bono said to a chorus of boos.

"Everytime you shout, he hears you!"