Perhaps Pearl Jam fans in Toronto should have seen this coming. Eddie Vedder was in Toronto for the Toronto Film Festival, Neil Young was in Toronto for the Toronto Film Festival ... the two enjoy getting together more than Skippy and Smuckers...

...So it shouldn't have been too surprising when Young joined Vedder and Pearl Jam during Sunday night's encore at the Air Canada Center. But of course it was.

During Pearl Jam's second encore, the Toronto born Young strapped on his guitar, strode on stage and jammed along as Vedder belted out the lyrics to 'Keep on Rockin' in the Free World.' The artists have done this song together with such frequency that it would be jarring to hear one without the other.

Vedder was likely at the Film Festival for the premiere of the third 'Paradise Lost' movie, covering the trial of the 'West Memphis Three.' The three men -- Damien Echols, Jessie Misskelley and Jason Baldwin -- were freed last month after spending 18 years in prison for murders they say they didn't commit. Vedder was a strong supporter of the group.

Young's film 'Neil Young Journeys' also premiered at the Toronto Film Festival.

The combo documentary/concert film centers on a two-night performance at Toronto's Massey Hall, but also follows the Canadian singer as he visits cities he grew up in.

Sunday night's show was the first of two for Pearl Jam at the Air Canada Center. They also played Monday night. The band is celebrating their 20th anniversary, and have frequently credited Young with helping them get this far. In the past Vedder has joked that his Seattle band would have lasted only “five or six years if Uncle Neil hadn’t been looking after us.”

Watch Pearl Jam and Neil Young Perform 'Keep on Rockin' in the Free World'