A mid-season time-out has paid quick dividends for Samantha Stosur with a confidence-boosting first title since her 2011 US Open triumph.

Stosur clubbed top-seeded Australian Open champion Victoria Azarenka 6-2 6-3 in the final of the Southern Californian Open on Sunday, the victory her first in nine career meetings with the world No.3.

Reversing her loss to Azarenka in her previous final in Doha last October, Stosur earned $A140,000 for her win, plus a rankings rise from 13th to No.11 in the world three weeks out from the US Open.

Her breakthrough came just three weeks after Florida-based Stosur recharged her batteries at home in Sydney, not picking up a racquet between Wimbledon and her return for the American hardcourt season.

Instead the Queenslander spent her down time chilling out and attending the Maroons' series-deciding State of Origin rugby league win over NSW at ANZ Stadium.

"This year has certainly been a little tough. I'm very, very happy now to get another win and hopefully that can mean some good things in the future," she said.

After a first-match loss in Stanford, Stosur was granted a wildcard into Carlsbad and ended up winning the title - the fourth of her career - with the same scoreline she achieved when she thumped Serena Williams at the US Open two years ago to secure her only grand slam crown.

Stosur blazed 20 winners and saved 11 of 12 break points against an out-of-sorts Azarenka, following up an impressive quarter-final win over world No.4 Agnieszka Radwanska - the first time she has defeated two top-five players in an event since the 2011 WTA Championships.

Azarenka later withdrew from this week's Toronto tournament citing a lower back injury, but Stosur was just glad to prove to herself again that she could thrive under tournament pressure.

"You can practice all you want, but at some point, you got to put it into play in matches," Stosur said.

"That was the reasoning behind coming here. You got to put yourself under that pressure of playing matches. That's why I came, and obviously now (I'm), very, very pleased with that decision."

Stosur has two more tournaments to prepare for Flushing Meadows and the 12th seed is full of confidence ahead of her first-round clash with qualifier Julia Glushko at this week's Rogers Cup in Toronto.

"This is a huge boost for me," Stosur said.

"I haven't had great results for really all year, so to be able to bounce back and come away with this is really exciting and a good boost going into the last slam of the year."