Savoy's clutch basket with 1:08 remaining produced the Seminoles' first lead of the second half and started a game-ending 7-0 run. Senior guard Braian Angola scored 16 points and sophomore guard Trent Forrest contributed 13 points and four steals to help Florida State (22-11) reach the Sweet 16 for the first time since 2011.
Savoy scored 11 points while senior forward Phil Cofer and junior guard Terance Mann scored 10 apiece for the Seminoles.
Senior guard J.P. Macura scored 17 points before fouling out and senior forward Kerem Kanter added 15 for the Musketeers (29-6). Freshman guard Paul Scruggs tallied 11 points but standout senior guard Trevon Bluiett had just eight points on 2-of-8 shooting in his final college game.
Florida State advances to face fourth-seeded Gonzaga on Thursday in Los Angeles.
The Seminoles hadn't forgotten that Xavier crushed them 91-66 in the second round of last year's NCAA Tournament.
"It feels good, it feels like sweet revenge," Mann said in a postgame interview on TNT. "We're back in the Sweet 16, so I am proud of my boys."
Xavier committed 18 turnovers while shooting 46.9 percent from the field. Florida State shot 43.6 percent and gave the ball away 14 times.
Savoy's shot made it 71-70, and he added two free throws with 21.6 seconds left to make it a three-point margin.
Xavier's chance to tie came up empty when Kanter air-balled a 3-point attempt with seven seconds remaining. Seminoles sophomore guard CJ Walker added two free throws with 6.5 seconds left to seal it.
A layup by Bluiett gave the Musketeers a 56-44 lead with 10:44 remaining. Florida State cut its deficit in half four-plus minutes later before Xavier pushed its lead back up to nine.
The Seminoles then made a dash with seven points in 67 seconds, capped by Forrest's three-point play to cut their deficit to 66-64 with 4:21 left. Florida State soon received back-to-back baskets from freshman forward Mfiondu Kabengele to knot the score at 68 with 2:21 left.
Scruggs made two free throws to give the Musketeers a two-point lead with 1:49 left.
Macura scored 10 first-half points as Xavier led 34-32 at the break.
The Musketeers used runs of 8-0 and 10-0 in the game's first 10 1/2 minutes to open up a 24-15 advantage.
--Field Level Media
Florida State | Xavier | |
Braian Angola 15 | Scoring | J.P. Macura 17 |
Braian Angola 3 | Assists | Quentin Goodin 2 |
Braian Angola 6 | Rebounds | Kerem Kanter 6 |
Trent Forrest 4 | Free Throws Made | Paul Scruggs 4 |
Trent Forrest 4 | Steals | Trevon Bluiett 2 |
Christ Koumadje 2 | Blocks | Kaiser Gates 1 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Florida State | 75 | 43.6 | 8-23 | 19-22 | 7 | 30 | 4 | 10 | 14 |
Xavier | 70 | 46.9 | 5-13 | 19-30 | 11 | 30 | 2 | 6 | 18 |