Jo Edwards was beaten by Canada's Kelly McKerihen at the World Bowls Championships today, but still remains on course to progress ©Getty Images

New Zealand's double Commonwealth Games champion Jo Edwards suffered a shock loss to Canada's Kelly McKerihen at the World Bowls Championships in Christchurch today but still remains on course for a play-off berth.

The 46-year-old, who claimed gold in the pairs event at Manchester 2002 and in the singles competition in Glasgow two years ago, was upset 21-16 by McKerihen in today's middle session.

Edwards had breezed through her first match with a 21-8 win over Kenya's sole competitor Susan Waruguru Kariuki.

But she came unstuck against McKerihen, a 2012 world singles bronze medallist.

All is not lost for Edwards, however, who recovered with a third match win over Wales' Laura Daniels, 21-12.

The top three bowlers from each of the two sections qualify for the next round which will take place on Friday (December 2).

Edwards will be backed to beat her opponents tomorrow, but her potential Thursday (December 1) clash with Australia's defending world champion Karen Murphy could be a potential classic.

Murphy surprisingly lost her third game today to Kenya's Kariuki, 21-16.

Australia's Karen Murphy was also hit by a surprising defeat ©Getty Images
Australia's Karen Murphy was also hit by a surprising defeat ©Getty Images

She opened her account with a 21-7 win over Cyprus' Frances Davis and followed that up by beating the United States' Kim Heiser, 19-13.

Malaysia's Manchester 2002 and Melbourne 2006 Commonwealth Games champion Siti Zalina Ahmad also suffered defeat as she lost 21-16 to Scotland's Lesley Doig in the first round.

Doig also edged Ireland's Catherine Beattie 21-18 before completing an incredible day with a 21-11 win against Norfolk Island's Carmen Anderson. 

Elsewhere on the opening day of action, the New Zealand women's four bounced back to beat South Africa 20-10.

Earlier in the day the hosts, skipped by 2008 world singles and pairs champion Val Smith, lost 17-14 to Singapore.

After beating the South Africans, New Zealand also claimed a 21-13 win over their Australian rivals.

In the men's pairs event, Glasgow 2014 gold medallists and 2012 world champions Alex Marshall and Paul Foster of Scotland enjoyed a mixed day.

They beat Cyprus 30-10 and followed that up with a 20-17 win over Singapore.

They then went on to lose their third clash to Australia's Aaron Wilson and Brett Wilkie.

Action is set to continue tomorrow where matches across the men's triples and pairs competitions and the women's singles and fours tournaments.