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
52-2
U Conn 105; Idaho 37 - 68 points - 3/23/2013
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.
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