Kashi Leuchs finds his rhythm before taking control of the 2009 Motatapu Icebreaker mountain bike race. Photo by Derek Morrison.

There was little Marcus Roy could do to rein in his Team RoadCraft team-mate Kashi Leuchs at the Motatapu Icebreaker mountain bike race on Saturday.

Roy, of Invercargill, had won the 43km sub-alpine mountain bike event on the previous four occasions, but Leuchs, of Dunedin, broke that winning streak after opening up a 30-second gap by the halfway point of the race.

Dunedin rider Tony Hogg set the early pace.

"Tony put the hammer down from the start and we had young Dunedin rider Jeff Notman with us as well," three-time Olympian Leuchs said.

"Tony was just hammering off the front and Jeff and I fell off the pace around the same time. I was struggling to breathe a bit.

"At that point I thought Tony had it in the bag, he was riding so strong," he said.

Roy kept with Hogg, but paid the price.

"I was really working just to hold on to Tony. I remember thinking, `This is going to be a long day'," Roy said.

Behind the leaders, Leuchs found his own rhythm and began to build his momentum.

He took the lead about the 15km mark.

"I just decided to ride my own pace and focused on my breathing and brought my whole system to a calmer state.

"By then I had improved my position and when we hit a short, sharp climb I felt good and passed Tony," Leuchs said.

Behind Leuchs, Roy caught and passed Hogg and found himself chasing hard for the lead.

"I could see Kashi ahead of me, in the saddle, out of the saddle, in the saddle, out of the saddle, just keeping the pressure on the whole time," he said. "About that point, I realised that I wasn't going to get back in touch with him."

Roy also feared his race record of 1hr 57min 47sec might be in jeopardy, but Leuchs crossed the finish line at Butlers Green, Arrowtown in 1hr 58min 42sec, nearly a minute outside Roy's record from last year.

Sara Macdonald, of Dunedin, was the first woman into Arrowtown, in a time of 2hr 29min 26sec.

About 2000 riders completed the 43km course, which traverses three private stations, Motatapu, Soho and Glencoe.

John Winsbury took the winner's crown for the third time in the marathon event.

Winsbury (33) demolished the 2006 race record by more than 5min, recording a time of 2hr 38min 13sec.

Winsbury's performance was driven significantly by the presence of Christchurch teacher Phil Costley (38) who, with about 40 national running titles to his credit, was expected to pose a serious challenge to the Australian physiotherapist.

The two runners made their own race from the start, clearing out from the rest of the more than 700 strong field in convincing style.

Fresh off a course record at the Buller Marathon, Costley was also nursing a slight hamstring injury.

"I thought it had come right [for Motatapu], but with about 18km to go I got some twinges," he said.

When he eased off, Winsbury made his move, eventually finishing 27min 20sec ahead of his rival.

The women's marathon was won by Kirsty Morris, of Dunedin, in 3hr 35min 22sec from Laura Callahan (3hr 41min 37sec).