Australia's Bree Walker seventh at halfway stage of inaugural Winter Olympic monobob competition in Beijing

Bree Walker is sitting in seventh place at the halfway stage of the Beijing Winter Olympics monobob competition at the Yanqing National Sliding Centre.

Walker is almost two seconds behind early leader Kaillie Humphries of the United States, but just 0.77 seconds off the provisional podium with two runs left to race on Monday.

The 29-year-old was sitting 10th after her first run, having been untidy through the uppermost section of the course.

She finished 1.11 seconds behind early pacesetter Humphries, who established a track record of 1 minute and 4.44 seconds in her first slide down the «Ice Dragon», reaching speeds of over 120 kilometres per hour.

With all runs counting towards a driver's overall time, being so far behind the leader all but rules Walker out of contention for gold barring a serious mistake from Humphries, who set the fastest time in both of her runs so far.

«I'm not making it easy for myself, that's for sure,» Walker said after completing her second run.

«The first run was very messy. The second run I cleaned it up a lot but I still had a big mistake after corner four.

»So we just have to come back tomorrow and clean it up some more and hopefully I can climb up a few more spots."

Walker's second run (1:05.54), which was 0.01 faster than her first (1:05.55), was the sixth fastest in the second round as several riders struggled with their lines through the tight and technical course.

The Australian topped the timing list in three of the six official practice runs prior to Sunday's opening two competitive efforts.

But she said conditions had changed significantly over the course of the first few days.

«The ice is a little bit harder because of the temperature, we're on more polished runners, but that's the conditions