Twenty-three-year-old Darren Lapthorne claimed the biggest success of his career to win the 163km men's elite road race at the 2007 Australian Open Road Championships in Bunninyong, near Ballarat, Victoria, on Sunday.

"It's the happiest day of my life," said Lapthorne who is studying a Bachelor of Business at RMIT in tandem with pursuing his cycling career. "It is an unbelievable moment for me and I'll never forget it."

Lapthorne crossed the line well clear at the end of 16 laps in a time of 4hr16min18sec with his Drapac Porsche teammate and Barcelona Olympian, Robert McLachlan, 35, of Canberra, sprinting home 15 seconds later to claim his third Australian Championship silver medal. Tasmanian Karl Menzies, 29, who rides with the American registered Healthnet professional team was third.

"The way it worked out with having my teammate up there as well, I never imagined it," said Lapthorne who launched a solo break from a leading group of eight riders with 14 kilometers remaining. "I was surprised to get away but once it got up to 30 seconds I thought it's going to come down now.

"But every time check was 30 sec, 30 sec and I thought if I just keep this tempo going I've got a chance and you just put your head down and keep going," said Lapthorne who's best previous result was winning the road race at the 2006 Australian Teams Championships in Queensland. "Today we came out and wanted to make a mark on the race and the main aim was to establish a break with the two of us in it (McLachlan and himself)... so it worked out well."

Lapthorne has his sights set on a career in Europe and hopes to race there this season with his Drapac-Porsche team, Australia's only registered Pro-Continental team.

McLachlan, who was second in 2005 In Echunga, South Australia, behind Robbie McEwen and in 2004 on Sunday's Bunninyong course behind Matt Wilson was consoled by the fact the man who beat him was his teammate.

"First and second on the podium is better than the win," said McLachlan. "I'm stoked to work for Darren, he's such a generous guy, he's never selfish and he'll lie down in front of a train for you.

"He was the strongest out there....he deserved it."

On the first lap of the race Menzies teammate and eight time Australian time trial champion, Nathan O'Neill, launched a solo attack to set the pace.

"We said to Nathan get in the early break but we didn't mean go solo off the front," laughed Menzies who also had teammate Rory Sutherland in the race. "He (O'Neill) loves that stuff."

On lap two O'Neill was joined by Simon Gerrans (AG2R-Prevoyance) and Chris Jongewaard. Gene Bates (SouthAustralia.com-AIS) later joined them but on lap eleven their bid was stymied when the main bunch reeled them in.

At that point the pressure was applied and the race splintered leaving 13 riders to fight it out over the last four laps. By two laps to go the lead group had whitled down to eight and as they approached the ascent of Mt Bunninyong Rd for the penultimate time Lapthorne jumped clear.

"When he went no one could follow him," said Menzies. "All credit to Drapac Porsche because it was awesome what they did (taking first and second)."