Rush’s ‘Limelight’ takes on the Guess Who’s ‘American Woman' in an all-Canadian Ultimate Classic Rock March Riff Madness round one competition.

Tears, beers and yes, a little blood was spilled, but we've selected 32 of classic rock's most iconic riffs and paired them off in 16 first-round duels. Over the next five weeks the field will be repeatedly cut in half by your votes, until we theoretically arrive at the most awesome riff in all of rock history.

This Global Rock region contest featured a face-off between distinctive riffs conjured by twin Great White North rock legends who have little else in common. The Guess Who frequently and unfairly deal with one-hit-wonder accusations, but even if that were true, what a hit! ‘American Woman’ boasts the sort of riff that countless bands would give their eye teeth for.

In contrast, intellectual power trio Rush has enjoyed one of the longest, most prolific and distinguished careers in rock. Their fame and acclaim comes in large part due to their albums, not their singles, but they too could churn out unforgettable riffs like the one in ‘Limelight.’

So which of these Canadian giants will come away with the hockey puck? You can vote once per hour until round one of March Riff Madness closes on Sunday, March 9 at 11:59PM Eastern. The final March Riff Madness winner will be revealed on April 7.

Watch Rush Perform 'Limelight'

Watch the Guess Who Perform 'American Woman'