The Elite Eight round of the N.C.A.A. women’s tournament begins on Sunday, bringing even higher stakes and tight matchups. In the Greensboro and Spokane regions, two No. 1 seeds will fight for the Final Four spots that they believe are rightfully theirs, and two lower seeds — one much lower — will try to spoil their party.

No. 1 seed South Carolina plays No. 10 seed Creighton at 7 p.m. Eastern (ESPN) in the Greensboro regional final, while No. 1 seed Stanford plays No. 2 seed Texas at 9 p.m. Eastern (ESPN) in the Spokane region.

The top overall seed, South Carolina, will face another big underdog.

According to ESPN, 3 percent of women’s basketball tournament brackets created using its platform had No. 10 seed Creighton in the Elite Eight. Even that seems high, and going farther is a tall order against South Carolina, a team whose dominance all season has only recently shown signs of faltering.

The Gamecocks won their round of 16 game on Friday against fifth-seeded North Carolina without posting gaudy statistics — at least not beyond forward Aliyah Boston’s 28 points and 22 rebounds. The Tar Heels stayed within reach until the end, and South Carolina had its second straight game in which it did not have enough separation to be comfortable until the clock ran out. Instead, the Gamecocks needed Boston to post numbers far higher than her season averages to survive, something Creighton is likely considering as it puts together its game plan.

In order to beat No. 3-seeded Iowa State, the Bluejays had to play impressive, consistent defense. The Cyclones had been one of the highest scoring teams in the country coming into the game, but Creighton was able to frustrate their best offensive weapon, crafty Iowa State senior Ashley Joens. She made just four shots from the field. The 6-foot-5 Boston will have to use her substantial size advantage over Creighton — which has no players taller than 6-foot-1 — to once again score consistently inside, even if the Bluejays can take away many of her guards’ open looks.

South Carolina will also need to guard the perimeter in order to clinch their second straight trip to the Final Four, which has been one of their strengths this season. On average, opposing teams make just 26.6 percent of their 3-point shots against the Gamecocks. They’ll need to match or surpass that average against Creighton, which has made 9.6 three-point baskets per game so far in this tournament while taking comparatively few shots. Although Creighton is fighting against the odds to become the first double-digit seed to make the Final Four, the game might very well come down to the wire.

No. 2 Texas will try to replicate their biggest upset of the season.

“That was a pretty long time ago,” said Texas freshman point guard Rori Harmon when asked about the Longhorns’ win over the Stanford, the reigning champion, back in November. “It’s completely different now.”

The Cardinal, it would seem, don’t quite see it that way. Texas beat them on their home court at the very game where they were celebrating their title and awarding players their championship rings. Stanford had a 5-point lead going into the fourth quarter of that game, and still lost — something coach Tara VanDerveer brought up when considering the matchup. “I don’t think anyone on our team has forgotten about that,” she said after Stanford’s round of 16 win.

Unfortunately for Texas, Stanford looked as intimidating as ever in its near-total domination of No. 4 seed Maryland. Its weakest quarter, though, was once again the fourth, in which the Terrapins were able to cut what had been a 26-point lead down to 6. The Longhorns see relentlessness, and specifically relentless defense, as their trademark, and will aim to once again fluster the Cardinal late.

The challenge will be stifling Stanford’s electric offense, powered by junior Haley Jones and a slew of other shooters with the size to create open looks from anywhere on the court. If they want to pull off the upset, the Longhorns’ post players will have to play careful, tight defense in order to draw Stanford’s Cameron Brink — one of the Cardinal’s most efficient scorers — into foul trouble, which can be one of her weaknesses.

Even if the Longhorns can slow Stanford down using the press defense, they will likely have to fight to score themselves. Joanne Allen-Taylor was the leading scorer for Texas in the round of 16, fighting for pull-up jumpers and drawing fouls. The senior will have to keep her energy high and the ball moving in order to find any offense at all against this experienced Stanford team.