Jason Kapono scored 12 points for Toronto, while Juan Dixon and Carlos Delfino finished with 10 apiece.
DeShawn Stevenson had 12 points for the Wizards.
The Raptors led from the outset Friday, making it look easy against a sloppy Wizards squad, and took a 29-point lead into the fourth quarter.
With a collection of bench players for both teams on the court for the final few minutes, the athletic Jamario Moon scored on an alley-oop dunk that brought the crowd to its feet with just less than two minutes to play. Luke Jackson sunk a 3-pointer the next time down the floor to make it 96-64 for Toronto, and the Raptors cruised to an easy win to finish their exhibition schedule 5-2.
The Wizards dropped to 4-4.
Toronto has looked solid in its past two games, and has plenty of reason to be optimistic about the regular season, which starts Wednesday when the Raptors host the Philadelphia 76ers in their opener.
Toronto shot 49 percent and held Washington to 37 percent shooting. The Raptors outrebounded the Wizards 47-30.
Raptors All-Star forward Chris Bosh made his second appearance in as many nights, after missing three games because of a sore left knee. The All-Star forward finished with eight points and three rebounds in 17 minutes.
"I think right now we're pretty good, I think we can be satisfied with where we are," Bosh said. "It's not like we're winning and giving up a bunch of layups, and letting teams score 100-plus points."
The Wizards were without All-Star guard Gilbert Arenas, who had offseason knee surgery, and had fluid drained from the knee earlier this week.
Bargnani, who turned 22 on Friday, played with poise, shooting 6-for-9 from the field and playing tough defense in his 23 minutes.
The big center led the way with 10 points and five boards in the first quarter, helping the Raptors take a 26-15 advantage into the second quarter.
The Raptors continued to put distance on Washington in the second, outscoring the visitors 25-11 to take a 51-26 lead into the dressing room at halftime.
A three by Kapono early in the third put Toronto up by 33 points, and the Raptors led 77-48 heading into the fourth.
"I never use the word 'happy' or 'pleased' but we feel we are going in the right direction and trying to make our guys believe that we are a good basketball team, and I tell them all the time," Raptors coach Sam Mitchell said.
Washington opens the season Wednesday night at Indiana.