Martine Rønning helped Norway to its fourth win in the World Mixed Doubles Curling Championship ©World Curling

Japan and Norway have extended their undefeated runs to four wins apiece at the World Mixed Doubles Curling Championship after day three at the Gangneung Curling Centre.

In their only match of the day, Chiaki Matsumura and Yasumasa Tanida overcame a scare at the halfway point to down England 12-7.

A massive four-point steal in the fourth end put father and daughter team Michael and Lina Opel into a surprise lead.

However, the Japanese pair responded with four of their own in both the fifth and seventh ends to force the English to throw in the towel before the eighth and final end.

The loss means that the Opel's are still in search of their first win in Group B as they sit level with Germany in joint last place.

Norway produced an inspired final three ends to snatch victory against neighbours Sweden and keep their win streak alive.

Martine Rønning and Mathias Brænden found themselves down to Therese Westman and Robin Ahlberg after steady scoring from the Swedes saw them lead 5-3 before their defences fell.

Both Japan and Norway are fighting for pole position in Group B, with the leader at the end of the round robin stage progressing directly to the semi-finals.

In Group A, there are three teams vying for the top spot.

Canada, Estonia and Scotland are tied on four wins and one loss after they all picked up two wins in today's action.

Canada got the better of Italy 8-4 and Australia 11-6 while Estonia secured comfortable wins over the Czech Republic and Hungary 12-6 and 9-2, respectively.

Scotland's Bruce Mouat and Jen Dodds forced hosts South Korea into an early resignation as they prevailed 11-6 before scraping past Olympic champions Italy 8-6.

They now face a crucial match against fellow table toppers Estonia tomorrow.

"The Estonians have a lot of experience and have had a lot of success this year as well, winning on the mixed doubles tour," said Dodds.

"We don't really need to change much, though and hopefully we can get off to another strong start.

"It'll be interesting to see what happens tomorrow, with the stones being rubbed, but if we just keep doing what we're doing that should get us into a good situation."