Villeneuve, racing on the Circuit Gilles Villeneuve track named after his father, made a desperate bid to pass Papis on the final lap, but fell short. Said and Papis raced side by side down the final stretch to the finish line, with Said winning by a nose and Villeneuve 0.214 of a second behind.
Said got the lead when Robbie Gordon ran out of fuel after the restart.
Nationwide series leader Brad Keselowski was fourth.
The pace car came out four times in the first 24 laps after on-track incidents but wasn't needed again until the 65th, when Michael Annett's engine blew. But it came out again after a pile-up on the 68th and after the 72nd when Jason Leffler went off the track.
Defending champion Carl Edwards led most of the race, but he began losing pace and with only nine laps to go, his wheels began to wobble from a rear axle problem. With the caution flag out, he went to the pits, giving Gordon the lead.
Villeneuve used the caution to pit for fuel and he battled through the yellow flags in the top five. After a 12:59 delay to clean oil from the track, plus a formation lap, the three final laps were added for a total of 77.
It was a big day for J.R. Fitzpatrick of Cambridge, Ont., who finished seventh. Only 10 cars of the 43 cars finished in the lead lap.
The fourth race at the home track for Formula One's Canadian Grand Prix saw warm sunny weather after two wet races and a large crowd jammed the grandstands and thousands more watched from trackside.
It was a tough day for Marcos Ambrose, who started from pole position and led early on, but developed a battery and a suspension problem and spent two laps in the pits. He rejoined the race in 30th spot but quit the race a few laps later. Ambrose has led the Montreal event all four times but has been plagued by bad luck.
Patrick Carpentier of Joliette, Que., saw his race end after 51 laps with a mechanical problem.
Both 2008 winner Ron Fellows of Toronto and D.J. Kennington of St. Thomas, Ont., were involved in minor incidents. Fellows retired after 53 laps, while attrition put Kennington 11th.
Andrew Ranger of Roxton Pond, Que., went into the race after having won the NASCAR Canadian Tire event earlier Sunday, but he was only two laps into his Nationwide race before he was forced to his garage with a badly damaged front end. He tried to rejoin the race 14 laps later but retired soon after.
"You start at the back and you catch traffic and people hit each other," the 23-year-old said. "I got hit in the back and hit the guy in front of me and broke the radiator. It's just bad luck."
Ranger and Michael McDowell started at the back after having to change engines during the weekend, while Gordon was at the back for making adjustments to his car.
It was the 25th race on the 35-event Nationwide schedule. The next race is Sept. 4 at Atlanta.
