The biggest challenge yet for the USC women’s tennis team starts Friday as they take on two Pac-10 foes in non-league matches today and Saturday at Marks Stadium.

USC’s matches this weekend do not count toward the Pac-10 standings but will play an important role when it comes to postseason seeding.

First up is today’s match versus No. 3 California (7-1). USC is 31-25 all-time against the Bears after beating them 4-3 in the teams’ only meeting last season at Marks Stadium.

Cal has three players ranked in singles: No. 2 Jana Juricova, No. 20 Marina Cossou and No. 75 Mari Andersson. Two Cal doubles teams are also ranked: No. 13 Andersson paired with Juricova and No. 54 Marina Cossou and Kasia Siwosz.

Saturday brings in the only undefeated Pac-10 team — No. 11 Stanford (7-0), who has posted shutouts in its last three meets.

USC is 18-57 all-time against Stanford after snapping a 50-match losing streak to the Cardinal with USC’s 5-2 win last season at Marks Stadium.

The Cardinal have five players ranked in singles: No. 13 Hilary Barte, No. 24 Mallory Burdette, No. 36 Lindsay Burdette, No. 54 Stacey Tan and No. 70 Carolyn McVeigh. Two Stanford doubles teams are ranked: No. 2 Barte and Lindsay Burdette and No. 37 Tan and Mallory Burdette.

The No. 10 Women of Troy (7-2) boast an undefeated record at home and are hoping to continue their success as Pac-10 champions from last year. This is their first meeting with Pac-10 opponents all season.

“It felt great last year beating both of them,” said junior Maria Sanchez of USC. “We just hope to go into this weekend with the same intensity and repeat that success.”

According to ITA ranking earlier this week, Sanchez (8-1) climbed in the singles rankings, as did USC sophomore Alison Ramos. Sanchez leads her team at No. 3 with Ramos following close behind at No. 19.

Two other teammates for the Women of Troy are ranked among the nation’s top 50. The two freshmen on the team, Danielle Lao and Valeria Pulido, are ranked No. 31 and No. 51, respectively.

The No. 31 doubles pair Pulido and Sanchez will team up against the Pac-10 foes as well.

“Playing against tougher schools the past few weeks has really gotten our energy going,” Lao said. “We’re ready to step it up and give it all we’ve got this weekend.”

“All of these big matches coming up are exciting opportunities for us to play in big, competitive matches,” USC coach Richard Gallien said. “The wins last year absolutely give us confidence. But we realize that was last year. Tomorrow is tomorrow.”

Today’s match begins at 1:30 p.m., while Saturday’s meet will start at noon.