Gonzaga opened as a 6.5- or 7-point favorite over South Carolina in the Final Four, depending on the book.
Pinnacle Sports opened the Zags as 6.5-point chalk, while BookMaker.eu opened the line at -7. Both books were dealing a total of 138.
The surprising Gamecocks (26-10) won the East Regional Sunday afternoon with a 77-70 victory over Florida at Madison Square Garden. It was seventh-seeded South Carolina's third straight win as an underdog.
CBS SPORTS: SOUTH CAROLINA REACHES FIRST FINAL FOUR
Gonzaga, the top seed out of the West, destroyed Xavier 83-59 on Saturday to improve to 36-1.
Both teams are making their first Final Four appearance.
"At this stage in the game, we know that the public is going to be all over Gonzaga at whatever number we put up," said Scott Cooley, odds consultant for BookMaker.eu. "But we have to be careful not to inflate the favorite number too much because there are professional bettors looking for underdog value."
Gonzaga is 16-4-2 ATS in its last 22 games against teams with .600-plus winning percentages. South Carolina has covered its last three NCAA Tournament games -- vs. Duke, Baylor and Florida -- by an average of 15 points.