They flew through the first round, but this weekend the stakes are higher and the opponents stronger.

After three wins on the road in Regional competition, the No. 4 Stanford softball team (43-14) returns home this weekend for a best-of-three battle with No. 11 Tennessee (59-13) for a trip to Oklahoma City and a spot in the Women’s College World Series.

Stanford was one of five teams from the Pacific-10 Conference to advance to the Super Regionals. The Pac-10, which consists of eight softball teams, was the nation’s only conference to see all its members selected to the 64-team bracket. Co-Pac-10 champs Stanford, No. 2 California and No. 3 Arizona advanced and will be joined by No. 12 UCLA and No. 21 Washington in the field of 16 remaining teams. Fourth co-champ No. 6 Oregon State failed to advance despite being seeded eighth at the beginning of the tournament. Arizona State and Oregon also did not make it out of the first round.

Stanford head coach John Rittman said that this year’s Stanford team is one of the best he has seen, comparing it to the two teams he took to the Women’s College World Series in 2001 and 2004.

“We have a lot of options with this team, a lot of depth,” Rittman said. “Different people have stepped up big in different times of the year. I think that this is the best offensive team we have had top to bottom in the lineup.”

Tennessee advanced to the Super Regional with three shutout victories over Miami University, Virginia Tech and College of Charleston. Ace pitcher Monica Abbott (45-7) gave up three hits while striking out 19 in the first two games, then threw a 10-strikeout no-hitter against Charleston.

Abbott is a smothering pitcher who boasts an incredible 0.51 ERA, holding opposing batters to a .121 average, with 553 strikeouts — an average of more than 10 per game — and has given up only 14 homers in 52 games.

“With Monica, we need to lay off of pitches out of the zone,” Rittman said. “We need to get pitches in the zone to hit and put the ball in play and then when we have runners in scoring position to get the timely hit, the clutch hit.”

Abbott could potentially give the Cardinal trouble in the batter’s box, but Stanford’s conference experience gives the team confidence heading into this weekend.

“We know they have a left-handed pitcher who throws hard and is pretty dominant,” senior catcher Leah Nelson said. “But we’re prepared. We see a lot of different pitchers in the Pac-10, so I think that has prepared us.”

In the batter’s box, Kristi Durant leads the Lady Vols with 75 RBI and is hitting at a .405 clip. Tennessee does not have a single dominant power hitter like Stanford’s freshman phenom Michelle Smith, but depends on contributions from the entire team, with six players posting at least 40 RBI on the season.

“They swing the bat very well,” Rittman said. “Their numbers are very good offensively, so we are going to have to play defense, make pitches. It’s going to be a good couple of games.”

The Cardinal advanced to the Super Regional with a perfect record in the Missouri Regional a week ago. They took the opener Friday against Robert Morris in a 9-0 rout cut short by the mercy rule, then beat No. 20 Southern Illinois on Saturday, 9-1. A much tougher 3-2 victory over No. 16 Missouri clinched Stanford’s spot in this weekend’s Super Regional.

Nelson led the charge at the plate, swinging a hot bat in the clutch. After hitting only seven homers all season, she hammered three out of the park last weekend, posting four RBI against Southern Illinois and bringing in all three of Stanford’s runs with a fourth-inning blast against Missouri.

“Obviously to come away 3-0 was very good,” Rittman said. “We didn’t need to play the ‘if’ game and I thought our team played very poised. We made some mistakes but we bounced back from the adversity and stayed together as a team. We got some big, huge clutch hits during the weekend.”

Freshman hurler Becky McCullough (21-6), who has emerged as Stanford’s ace in her rookie season, started all three games and pitched two complete, giving up three runs on 11 hits with 13 strikeouts in 18 innings of work. Junior Laura Severson (15-6) pitched two shutout innings against Robert Morris in relief.

“Becky pitched extremely well,” Rittman said. “And Laura came in against Robert Morris for a few innings and gave us real solid innings there.”

“It’s fun, very exciting to get it going,” McCullough said. “And three wins — you can’t really go wrong with that.”

Tennessee and Stanford have only met three times, once for a doubleheader in 1997 and once in 2000. The Cardinal won all three games and have outscored the Lady Vols 21-1 all-time.

The Super Regional format, which has been used for several years in baseball playoffs, was introduced to softball this year.

“I don’t know if there is that big of a difference in the competition or the teams that are going to end up in the World Series,” Nelson said. “Right now, it just feels like there are more games. It’s nice, more celebration when you win. I like that.”

McCullough said she does not see much difference between the round-robin format of the Regional and the Super Regional series.

“Last weekend we took the games one game at a time and looked at each opponent,” she said. “This is going to be the same thing. We’ve just got to win each game. We’re not going to really worry about their game and just try to stick to our game plan.”

The Cardinal and the Lady Vols face off today at 6 p.m. and Saturday at 1 p.m. at Boyd and Jill Smith Family Stadium. In the event of a split, the “if” game will be added to make Saturday a doubleheader. Though Stanford has split some doubleheaders this season, it has not lost the second game, which would decide the series winner if played.

“We’ve tried to do our research on them and we’re just going to see what happens when we get out there,” Nelson said. “I think we’re playing great right now. We’re peaking at just the right time.”