Team Sky's Richie Porte rode to an emphatic solo victory on Willunga Hill as Simon Gerrans reclaimed the race lead at Tour Down Under.
Tasmanian Porte leapt clear of his rivals with two kilometres to go on the famous climb and turned the screw on the steep slopes to claim stage five by a margin of 10 seconds.
The result and bonus seconds elevated Porte up to fourth on the general classification, 10 seconds back on new leader Simon Gerrans (Orica-GreenEdge).
The fight for the ochre jersey provided thrilling action with overnight leader Cadel Evans (BMC Racing) believing attack was the best form of defence of his seven-second lead.
With his team upping the pace it was Evans who hit out first on the fan-lined climb, dragging Porte with him as Gerrans was forced to come across the gap. Sensing his moment Porte bolted, putting daylight into Evans, who saw Gerrans and Diego Ulissi (Lampre-Merida) draw up alongside him.
Ulissi edged Gerrans in the sprint for second after the pair had distanced Evans to the tune of four seconds at the line, meaning the jersey changed hands by the slenderest of margins - one second.
The action looks set to go down to the wire with the top four in the standings separated by just 10 seconds going into the final stage criterium in Adelaide.
"The guys were absolutely incredible today," said Porte after the stage. "It was a little bit of a shame on the Corkscrew stage as I was a little bit out of position and lost some time.
"But I felt great coming into today. The team had a plan and the boys were incredible. Ian Stannard and Geraint Thomas were there to the last minute. They dropped me off right on the front at the start of the climb and victory is credit to all those guys.
"It's January and I'm not in top form just yet. To win in Australia and on this climb is a very special victory."
Battle on Willunga
With 151.5km on the agenda, the reputation of the queen stage preceded it with all eyes on the Willunga Hill finale.
The opening exchanges saw four riders slip away as Jens Voigt (Trek Factory Racing), Mikhail Ignatiev (Katusha), Juan Jose Lobato (Movistar) and Matteo Trentin (Omega Pharma - Quick-Step) took advantage of a peloton easing their way in.
The quartet carved out a gap of 8:37 over the bunch as BMC Racing looked content to tap out a tempo on the front. That didn't suit every team in the race and it wasn't long before Team Sky and Orica-GreenEdge hit the front.
With the wind whipping up and the focal point of the day approaching the pace upped around the circuit, Bernhard Eisel putting in a huge shift for Team Sky on the front.
First time up Willunga Hill the overall contenders were content to sit back and look at one another amid huge crowds on the climb. The duo of Voigt and Trentin made it further than many expected before finally being swept up with 16km to go.
The main group split over the top of the climb as Orica-GreenEdge turned the screw but Porte and Geraint Thomas had Ian Stannard for support heading onto the final ascent where he did the rest.