Dedrick Finn added 14 points and six assists. Anthony Myles and Justin Doellman each scored 11 for the Musketeers (10-9, 2-5).
Ramod Marshall scored 21 points to lead the Flyers (17-3, 7-0) and was named Blackburn-McCafferty Most Valuable Player of the Game.
Saturday’s game was tied at 64 with just under three minutes left, but a three from Sato with 1:25 left in the game was the only scoring the Musketeers would get down the stretch.
The teams played through 13 lead changes and seven ties in the game.
The Musketeers were up 11-10 six and a half minutes into the contest, but the Flyers countered with an 8-0 run to pull ahead 18-11 with nine minutes left in the first half.
UD built the lead to nine, going up 25-19 with six minutes left in the first half.
The Musketeers scored on seven of their final 10 possessions in the last 5:15 of the period as the teams exchanged the lead five times before drawing to a 34-all tie at halftime.
Sato fueled the Xavier run with 11 points, including three three pointers.
Xavier jumped out to an early second half lead by scoring the first nine points of the period.
Twice more XU built the lead to nine points in the early going of the second stanza, last holding that advantage at 51-42 with 13:22 showing on the clock.
The Flyers used a 15-3 run to go up 57-54, but Finn knotted the game 57-all with seven and a half minutes left to play.
Xavier would hold its last lead of the day at 60-59 after a Sato free throw with 5:12 remaining. The Flyers regained the lead on a Marshall three just 20 seconds later, and never allowed XU to regain an advantage.
Keith Waleskowski finished with 17 points and nine rebounds for the Flyers, and Sean Finn tallied 15.
Xavier still maintains its 24-15 edge in the battle for the Blackburn-McCafferty trophy that has raged since 1981, but UD now holds a 78-57 lead all-time in the series
The Musketeers will return to action on Tuesday night at Cintas Center for the annual Crosstown Shootout against the University of Cincinnati. Tip off is set for 7 p.m. The game will be broadcast on ESPN2.