Scottie Reynolds scored 25 points, and Corey Stokes added 20 Sunday, helping the 12th-seeded Wildcats reach the round of 16 for the third time in four years with an 84-72 victory over tiny Siena.
Villanova (22-12), one of the last teams picked for the tournament field, advanced to the Midwest Region semifinals in Detroit, where it will revert to an underdog role against top-seeded Kansas (33-3).
And the way the Jayhawks have been playing, the Wildcats can only hope to take some of Tampa's upset mystique with them to Motown.
"They have had a terrific year. They're playing really well right now," Villanova coach Jay Wright said. "We're going to enjoy this win, go back home, and just get back to work."
The Wildcats rallied from an 18-point deficit to beat fifth-seeded Clemson in the opening round. Sunday's win, their fifth in six games, gave Upset City -- as Tampa was dubbed after its first-day shockers -- a sense of normalcy.
The tournament pod here had four lower seeds win opening-round games for the first time in NCAA history. Villanova ended the streak, eliminating the 13th-seeded Saints (23-11) with a fast start and superior play at just about every position.
The Wildcats improved to 7-3 in the NCAAs under Wright. They reached the regional semifinals three years ago, where they lost to North Carolina. They lost to Florida in the Elite Eight in 2006.
Siena, which had been hoping to become the tournament's next George Mason, was overmatched from the start and never led.
At one point early in the second half, Reynolds and Stokes had outscored the Saints by themselves.
The Villanova guards got some timely inside help from Dante Cunningham and Dwayne Anderson down the stretch after Siena pulled within nine with less than seven minutes to go.