Sonoma, California – Renger van der Zande, of Nijmegen, The Netherlands, won Sunday's Round 19 GT race at Sonoma Raceway, at the Pirelli World Challenge Grand Prix of Sonoma presented by Kia. Frankie Montecalvo, of Highlands, N.J., won in GTA, while Colin Thompson, of Doylestown, Pa. won the GT Cup presented by MOMO Round 17.

From the standing start, second-on-the-grid van der Zande, in the No. 31 EFFORT Racing/World PMO Porsche 911 GT3R passed pole sitter Robert Thorne, of Littleton, Colo., in the No. 6 K-PAX Racing McLaren 650S GT3. Thorne's teammate and Saturday's Round 18 winner Kevin Estre, of Lochau, Austria, in the No. 9 K-PAX Racing McLaren 650S GT3 slotted into third.

As the field snaked through turn 2, a number of cars collided bringing out a full-course caution. Mike Skeen, of Charlotte, N.C., in the No. 2 DeVilbiss/Hawk Performance CRP Racing Audi R8 LMS ultra, as well as Peter Cunningham, of Milwaukee, Wis., in the No. 42 RealTime/Acura Motorsports/HPD Acura TLX-GT, Chris Dyson, of Pleasant Valley, N.Y. in the No. 16 Bentley/Breitling/Mobil 1 Team Bentley Dyson Racing Bentley Continental GT3, and Michael Lewis, of Laguna Beach, Calif., in the No. 41 EFFORT Racing/Curb-Agajanian Porsche 911 GT3R all retired from the race due to damage from the incident.

In GTA, class pole sitter and class championship points leader Montecalvo, in the No. 66 Bayshore Racing DragonSpeed Mercedes-Benz AMG SLS GT3 launched cleanly into the lead, sixth overall in the race. Due to the turn 2 incident ahead of them, GT Cup competitors started under yellow with pole sitter and class championship points leader Thompson, in the No. 11 Porsche of Bucks County/Penn Valley Constructors/Sherwin Williams Automotive Finishes/Austin Hatcher Foundation Kelly-Moss Motorsports Porsche 911 GT3 Cup assuming the lead.

GT drivers' championship contenders Olivier Beretta, of Monte Carlo, Monaco, in the No. 61 Ferrari of Ontario /Toronto /Alberta R. Ferri Motorsport Ferrari 458 GT3 Italia slotted into fourth, while Johnny O'Connell, of Flowery Branch, Ga, in the No. 3 Cadillac Racing Cadillac ATS-VR GT3 slotted into 7th.

On the lap 4 restart, van der Zande led through turn 1, as K-PAX teammates Thorne and Estre went side by side through turns 2 and 3. Estre completed the pass to move into third. Estre was awarded the Cadillac ATS-V Move of the Race for the pass.

In GTA, Montecalvo continued to lead in class, 7th overall, with Eric Lux, of Buffalo, N.Y. in the 08 Rembrandt Charms/Monticello Motor Club DragonSpeed Mercedes-Benz AMG SLS GT3 and Henrique Cisneros, of Miami, Fla., in the No. 30 MOMO NGT Motorsport Ferrari 458 GT3 Italia in second and third respectively in class, and 10 and 11th overall in the race.

Thompson led Saturday's GT Cup Round 16 winner Alec Udell, of The Woodlands, Texas, in the No. 17 Amsource Capital/Panther Pipeline GMG Porsche 911 GT3 Cup and Sloan Urry, of Salt Lake City, Utah, in the No. 02 Security National/Engel & Volkers TruSpeed Autosport Porsche 911 GT3 Cup.

By lap 7, van der Zande had built an .819 second lead over Estre, and through lap 10 he increased his lead to .844 seconds. In GTA, Montecalvo still led Lux, while Martin Fuentes, of Mexico City, Mexico, in the No. 07 Scuderia Corsa/Hublot/Samsung/Under Armour Scuderia Corsa Ferrari 458 GT3 Italia moved into 3rd in GTA, 12th overall in the race. Cisneros, who had been running third in the class was issued a drive through penalty for contact on the standing start.

On lap 12, Andy Pilgrim, of Boca Raton, Fla, in the No. 8 Cadillac Racing Cadillac ATS-VR GT3 closed up on Beretta and hounded the driver of the No. 61 machine but was never able to pass. Up front, van der Zande and Estre pulled away from the pack, building a roughly 30-car gap on Thorne, Beretta and Pilgrim. On lap 20 as Thorne went wide attempting to pass lapped traffic through turn 11, Beretta passed the driver of the No. 6 car to move into third.

At the checkered, van der Zande took his first career Pirelli World Challenge win, ahead of Estre, and Beretta. Thorne and Pilgrim battled furiously on the last lap with Pilgrim passing Thorne through turn 7, only to have Thorne come back and pass for position as the two came to the stripe. In GTA, Montecalvo, scored his 7th win of the season over Lux and Fuentes, while in GT Cup, Thompson won his 12th race of the season with Udell and Urry finishing second and third.

"Winning today is fantastic," said van der Zande. "The car improved a lot overnight, and for me it's the first time doing well with a Porsche and driving it to the limit. For sure yesterday the car wasn't great, the tire pressure was maybe a little too high, but also me pushing a little too hard on it, so getting back today and managing the tire all the way through the race, managing the gap between Kevin Estre was very good. Estre is one of the best drivers in the world in GT, so being in front of him really makes me proud."

On winning his seventh race of the season and taking a commanding lead in the GTA Drivers' Championship, Montecalvo said "we started the season with some ups and downs, so it was really hard for us to make up the points. After all the hard work we put in on the car, we just put our heads down, got some good luck and stayed out of trouble."

"I can't ask for anything more from Jeff Stone and the Kelly Moss Motorsport boys," said Thompson. "They give me the car to win every single weekend, and with a 3rd yesterday and 1st today, it is a good weekend. We've got to be proud with what we have done with the Porsche and I'm looking forward to the finale at Mazda Raceway Laguna Seca."

Of note, Drew Regitz, of Denver, Colo., in the No. 19 WWW.IRACERCOACHING.COM Audi R8 LMS ultra won the Optima Batteries Best Standing Start Award for gaining nine positions when the lights went out. Regitz also won the VP Racing Fuels Hard Charger Award for gaining 10 positions during the race. Pilgrim won the Invisible Glass Clean Pass of the Race Award for his pass on Thorne on the last lap of the race. MOMO Turning Point of the GT Cup race was Thompson cleanly getting through traffic maintain his lead.

Results are provisional until posted final. In GT, O'Connell leads Beretta in Drivers' Championship points (1625-1599), Montecalvo continues to lead in GTA, and Thompson leads in GT Cup. GT, GTA and GT Cup drivers now head to the finale weekend of the 2015 season Sept. 11-13 at Mazda Raceway Laguna Seca. Watch the races from Sonoma Raceway on CBS Sports Network, Sunday, September 6, at 2 p.m. Eastern.

Results from Sunday's 30-lap, 71.55 mile Pirelli World Challenge Championship GT/GTA Round 19, GT Cup Round 17 race, part of the Grand Prix of Sonoma presented by Kia at Sonoma Raceway, with finishing position, class, starting position in parentheses, driver, hometown, car, laps and reason out (if any).

1. GT, (2), Renger van der Zande, Nijmegen Netherlands, , Porsche 911 GT3R, 30.
2. GT, (4), Kevin Estre, Lochau Austria, , McLaren 650S GT3, 30, -2.186.
3. GT, (5), Olivier Beretta, Monte Carlo, , Ferrari 458 GT3 Italia, 30, -22.365.
4. GT, (1), Robert Thorne, Littleton, Colo., McLaren 650S GT3, 30, -25.050.
5. GT, (8), Andy Pilgrim, Boca Raton, Fla., Cadillac ATS-VR GT3, 30, -25.324.
6. GT, (11), JD Davison, St Petersburg, Fla., Nissan GT-R GT3, 30, -27.478.
7. GT, (3), (A)Frank Montecalvo, Highlands, N.J., Mercedes Benz AMG SLS GT3, 30, -31.023.
8. GT, (9), Johnny O'Connell, Flowery Branch, Ga., Cadillac ATS-VR GT3, 30, -32.514.
9. GT, (10), Bryan Heitkotter, Fresno, Calif., Nissan GT-R GT3, 30, -32.969.
10. GT, (14), (A)Eric Lux, Buffalo, N.Y., Mercedes Benz AMG SLS GT3, 30, -37.475.
11. GT, (19), (A)Martin Fuentes, Mexico City, Mexico, Ferrari 458 GT3 Italia, 30, -46.984.
12. GT, (12), Guy Smith, Beverley, England, Bentley Continental GT3, 30, -1:12.421.
13. GT, (21), (A)Henrique Cisneros, Miami, Fla., Ferrari 458 GT3 Italia, 30, -1:25.810.
14. GT, (22), (A)Christina Nielsen(R), Aarhus, Denmark, , Aston Martin Vantage GT3, 30, -1:26.387.
15. GT, (26), (A)Drew Regitz, Denver, Colo., Audi R8 LMS Ultra, 29, -1 lap.
16. GT, (24), (A)Bill Ziegler, Ponte Vedra, Fla., BMW E89 Z4 GT3, 29, -1 lap.
17. GT, (15), Ryan Eversley, Atlanta, Ga., Acura TLX-GT, 29, -1 lap.
18. GT, (25), (A)Eduardo Cisneros(R), Miami, Fla., Ferrari 458 GT3 Italia, 29, -1 lap.
19. GT, (20), (A)Bret Curtis, Austin, Texas, BMW E89 Z4 GT3, 27, -3 lap.
20. GT, (17), (A)Henrik Hedman, Ft Lauderdale, Fla., Mercedes Benz AMG SLS GT3, 27, -3 lap.
21. GT, (16), Duncan Ende, Los Angeles, Calif., Ferrari 458 GT3 Italia, 5, -25 laps.
22. GT, (23), Peter Cunningham, Milwaukee, Wis., Acura TLX-GT, 1, -29 laps.
23. GT, (13), Chris Dyson, Pleasant Valley, N.Y., Bentley Continental GT3, 1, -29 laps.
24. GT, (7), Michael Lewis(R), Laguna Beach, Calif., Porsche 911 GT3R, 1, -29 laps.
25. GT, (6), Mike Skeen, Charlotte, N.C., Audi R8 LMS Ultra, 0, -30 laps.
26. GT, (18), (A)Mike Hedlund, Woodside, Calif., Ferrari 458 GT3 Italia, 0, DNS.
27. GTC, (27), Colin Thompson, Doylestown, Pa., Porsche 911 GT3 CUP, 29.
28. GTC, (28), Alec Udell, The Woodlands, Texas, Porsche 911 GT3 CUP, 29, -4.954.
29. GTC, (29), Sloan Urry, Salt Lake City, Utah, Porsche 911 GT3 CUP, 29, -8.693.
30. GTC, (30), Lorenzo Trefethen(R), Napa, Calif., Porsche 911 GT3 CUP, 29, -30.636.
31. GTC, (31), Victor Gomez(R), San Juan, Puerto Rico, Porsche 911 GT3 CUP, 29, -46.038.
32. GTC, (32), Mitch Landry, Lake Charles, La., Porsche 911 GT3 CUP, 28, -53.671.
33. GTC, (33), Preston Calvert(R), Potomac, Md., Porsche 911 GT3 CUP, 28, -1:25.444.
34. GTC, (34), Phil Fogg Jr, Allendale, N.J., Porsche 911 GT3 CUP, 0, DNS.

Time of race: 50 minutes, 54.748 seconds.
Average speed: 84.321 mph
Margin of victory: 2.186 Seconds

Lap leaders: Laps 1-30, #31 Renger van der Zande
Fastest race lap: #31 Renger van der Zande, 1:34.315 (91.035 mph)
Fastest qualifier: #6 Robert Thorne, 1:34.554 (90.805 mph)

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