Point guard Cory Joseph had 17 points and seven assists as Canada improved to 3-1 in Group A of the tournament.
Bruno Fitpaldo led Uruguay (2-2) with 18 points in a game that started five hours late due to a power outage.
The Canadians will play Mexico on Thursday in their first game of the tournament's second phase.
Canada built a healthy 29-11 lead after one quarter. Joseph led Canada in the opening 12 minutes with 10 points and four assists.
By the end of the half Canada had more than doubled Uruguay with a 51-25 advantage. Nicholson carried the scoring load for the Canadians in the second quarter, finishing the half with 13 points.
Uruguay played better in the second half, but Canada still added to its lead, outscoring their opponents 24-23 in the third quarter.
The final quarter was the only period where Uruguay out-played Canada. The South Americans bested the Canadians 19-18 in the fourth.
Canada has four NBA players on its roster for the tournament. Nicholson plays for the Orlando Magic, Joseph is with the San Antonio Spurs, centre Joel Anthony is on the Miami Heat and forward Tristan Thompson is a member of the Cleveland Cavaliers.
The FIBA Americas Championship is a qualifying tournament for the 2014 FIBA Basketball World Cup in Spain.