Here it is. We're down to the last two. Heart's 'Barracuda' takes on the Kinks' 'You Really Got Me' in the final round of Ultimate Classic Rock's March Riff Madness.

Four weeks ago, we began by putting 32 of rock's most iconic riffs in a head-to-head bracket competition. Now, there are only two songs left in our month-long quest to theoretically arrive at the most awesome riff in all of rock history.

To get to the finals, 'Barracuda' took on some of the biggest American rock bands of all time. In the semis, they beat Aerosmith's 'Walk This Way,' and before that they emerged victorious over Van Halen's 'Unchained,' Guns N' Roses' 'Welcome to the Jungle' and Motley Crue's 'Kickstart My Heart.' The Kinks had to go the global route, beating Motorhead's 'Ace of Spades,' AC/DC's 'Back in Black,' Led Zeppelin's 'Whole Lotta Love' and Rush's 'Limelight.'

It's the Wilson sisters against the Davies brothers. Everyone can vote once per hour until the finals of March Riff Madness closes on Tuesday, April 8 at 9 AM ET. That's right, we're keeping the voting open longer than usual. We will reveal the winner later that day.

Watch Heart Perform ‘Barracuda’