The 29-year-old, from Wisconsin, took control of the women’s standings with three wins and one defeat at the Baxter Arena, in Omaha.

It is far closer in the men's standings where squads led by skips John Shuster and Heath McCormick are tied on top with 4-1 records.

But with two more days of qualifying remaining, there is still all to play for in terms of qualification for the Winter Olympics.

The top two teams in each group advance to the best-of-three finals that begin on Thursday (November 16) to determine which quartet will represent the US in South Korea.

Roth's team opened the day with a 9-2 victory over Cory Christensen’s team before winning a thriller 8-7 over Jamie Sinclair’s reigning national champion team which went to an extra end.

The game was tied 5-5 going into the ninth end but Roth took a vital two-point lead into the 10th. 

Roth and her teammates, Tabitha Peterson, Aileen Geving and Becca Hamilton, came through in the 11th and deciding end.

“We kept it fun, relaxed and played well,” Roth said. 

"We were comfortable if it went to an extra end.

"We’re just taking it one step at a time.

"This is a situation we’ve worked to put ourselves in for a couple of years, so we’re going to have fun and try to enjoy every moment."

After winning their first three games, Shuster’s team had lost its first match of the trials, 8-5 to Todd Birr’s team in the morning session. 

That win put Birr’s squad at 2-2 and left Shuster facing a crucial game against Brady Clark.

"We actually played a half-decent game, but Todd's team played an awesome game," Shuster said. 

"We dug ourselves a little hole early but we rallied to play solid ends three through 10."

Shuster's team trailed Clark by three points after the first two ends before scoring two in both the third and fourth ends, along with one in the fifth, for a 5-2 lead. 

Clark tried to rally but fell short.