1965 regional - Princeton 110 - Providence 70
52
The largest margin of victory was 30 pts in a champtionship game. Not sure about just tournament games.
69 points1963, South Regional First RoundLoyola 111, Tennessee Tech 42
45
In 1963, Loyola set the NCAA tournament record for largest margin of victory (69 points) with a 111-42 victory over Tennessee Tech in the first round.
52-2
U Conn 105; Idaho 37 - 68 points - 3/23/2013
7
I'm pretty sure UNLV beat Duke by 30pts in the 1990 title game
Houston
The largest margin of victory recorded in a horse race was by Secretariat in the Belmont Stakes in 1973, where he won by 31 lengths.
Largest Margin of Victory: Sam Morgan vs Forrest Petz at Ultimate Fight Night 6: One judge scored the fight 30-23 2nd largest margin: Nate Quarry vs Kalib Starnes at UFC 83: One judge scored the fight 30-24