(Sean Quentin Lee is a regular BPL contributor on cycling.)

A thrilling ride up the final ascent of Arthur's Seat has seen young Queensland rider Nathan Haas (Genesys Wealth Advisers) take the overall lead after the fourth stage of the Jayco Herald Sun Tour.

Although the stage was won by Russia's Egor Silin (Katusha), all eyes were on the 22-year-old Haas, who lived up to his potential by dropping the highly fancied Jack Bobridge (Garmin-Cervelo) before the line. Emotion overtook the young rider as he realised the enormity of his achievement.

Rhys Pollock (Drapac Professional Cycling) started the day as race leader, 15 seconds ahead of Haas, and for much of the day his team controlled the race, setting a steady tempo and keeping a breakaway of five riders within striking distance. But with 40 km to go and approaching the second climb of Arthur's Seat, WorldTour heavyweights Saxo Bank-SunGard and Garmin-Cervelo began to apply pressure, stringing out the peloton and disrupting the race leader's support.

The second ascent of Arthur's Seat saw the peloton split into several groups. While Pollock fell off the pace, Haas and pre-stage favourites Bobridge and Matthew Lloyd (Mitchelton Australian National Team) looked comfortable among the leaders.

Some frantic pacing by Drapac brought Pollock back to the leaders as the race looped back to the base of Arthur's Seat, but the effort was too much and Pollock was dropped again at the start of the third and final ascent.

With Pollock out of the picture, Haas became the 'virtual' leader of the race. His biggest threat was to come from Bobridge who started the day just eight seconds behind him, and he stuck to his wheel like glue. Lloyd, who had looked so comfortable on the earlier climbs, fell away, the former Giro d'Italia King of the Mountain winner unable to match the pace of the young tyros.

The Russian, Silin, attacked half way up the climb and established a stage winning lead, but the real race was happening behind him. Bobridge and Haas were trading blows.

With Haas only needing to stay on Bobridge's wheel to claim overall victory, it was up to the later to try and establish some sort of break over his opponent. Instead, the irrepressible Haas rode up along side of Bobridge and led him to the summit, crossing the line a bike length ahead of the Australian road champion to take second place and claim the overall leader's yellow jersey.

Haas, who has dominated the Australian domestic season, stood on the finish line in disbelief, an honest display of raw emotion washing over his face, one moment grinning, the next fighting to hold back tears as he embraced family and friends.

With only one stage left, a criterium centred around Melbourne's Lygon street, Haas seems assured of victory although sprint time bonuses could come into play. He leads second placed Bobridge by 10 seconds, with Denmark's Jonas Aen Jorgensen (Saxo Bank-SunGard) a further 19 seconds back in third place. Pollock, who has held the leader's jersey since stage one has dropped back to sixth overall, 1'14'' off the pace.

Haas also maintains his lead in both the points and young rider classification, while fellow Aussie Cameron Peterson (V Australia) takes over the King of the Mountain jersey after being the last surviving member of the five man breakaway.