Kennington, who qualified fifth for the race earlier in the day, had to drop to the back of the field for the start of the race after making unapproved adjustments to his car.
The 2010 series champion from St. Thomas, Ont., charged ahead in his No. 17 Castrol Edge/Mahindra Tractors Dodge - moving into the top five by Lap 27. He took the lead a quarter of the way through the race and only relinquished it for a short time after a round of pit stops.
Mark Dilley finished second to Kennington, with J.R. Fitzpatrick finishing third. Jeff Lapcevich and Jason Hathaway were fourth and fifth, respectively. Steve Mathews, Andrew Ranger, Ron Beauchamp Jr, Steve Cote and Noel Dowler completed the top 10.
Kennington became the fifth different winner in six series visits to the half-mile oval formerly known as Mosport Speedway.
Defending series champion Scott Steckly, who won last year's event, encountered mechanical trouble before the race started and was laps down to the leader throughout the race.
Pete Shepherd III - who won his second career pole award in qualifying - led the early stages of the race, but experienced mechanical problems late in the event.
The race was slowed due to caution five times for 36 laps and the lead changed hands four times among four drivers.
This was the third race of 2012 for the NASCAR Canadian Tire Series, the first of seven oval-track events on a 12-race schedule.
In the point standings, Fitzpatrick has just a single-point lead over Kennington with Ranger six points off the pace in third.
The Clarington 200 will be telecast by TSN on Sunday, June 24 at 1 p.m. ET and the RDS2 premiere is set for Wednesday, July 11 at 10 p.m. ET.NASCAR CANDADIAN TIRE SERIES-Clarington 200 UNOFFICIAL Results
Saturday: Canadian Tire Motorsport Park Speedway
Lap length: 0.5 miles
(Start position in parentheses)
1. (5) D.J. Kennington, St. Thomas, Ont., Dodge, 200 laps, 63.147 mph.
2. (7) Mark Dilley, Barrie, Ont., Ford, 200.
3. (3) J.R. Fitzpatrick, Cambridge, Ont., Chevrolet, 200.
4. (8) Jeff Lapcevich, Grimsby, Ont., Dodge, 200.
5. (6) Jason Hathaway, Dutton, Ont., Dodge, 200.
6. (2) Steve Mathews, New Liskeard, Ont., Ford, 200.
7. (9) Andrew Ranger, Roxton Pond, Que., Dodge, 200.
8. (10) Ron Beauchamp, Jr., Windsor, Ont., Dodge, 200.
9. (11) Steve Côté, Ile Bizard, Que, Chevrolet, 199.
10. (20) Noel Dowler, Sherwood Park, Alta., Dodge, 199.
11. (15) Jason White, Sun Peaks, B.C., Dodge, 199.
12. (14) L.P. Dumoulin, Trois-Rivieres, Que., Dodge, 198.
13. (16) Joey McColm, Ajax, Ont., Dodge, 196.
14. (4) Scott Steckly, Milverton, Ont., Dodge, 194.
15. (19) Ray Courtemanche Jr., Montreal, Que., Dodge, 193.
16. (1) Pete Shepherd, III, Brampton, Ont., Dodge, 158, axle.
17. (12) Larry Jackson, Oakville, Ont., Dodge, 144.
18. (18) Hugo Vannini, Repentigny, Que., Ford, 128, engine.
19. (13) Martin Roy, Napierville, Que, Dodge, 83, oil line.
20. (17) Howie Scannell Jr., Milton, Ont., Dodge, 34, overheating.
21. (21) Mike Scholz, Sault Ste. Marie, Ont., Chevrolet, 5, clutch.From Shon Sbarra / NASCAR