Transmission problems caused Brad Keselowski's car to slow down suddenly at Martinsville Speedway, which in turn collected four other cars behind him when Casey Mears rear-ended Keselowski's car and caused a red flag at the race. Ouch!

Martinsville Speedway is the smallest track on NASCAR's schedule, and that means there will be contact. Like the Camping World Truck Series , yesterday's Sprint Cup outing was punctuated by many yellow flags from contact and spins on the tight, narrow speedway.

Martinsville Speedway is a bit shorter than many other tracks on the NASCAR schedule, therefore,…

Keselowski's car was running in the top ten on lap 436 of 500 when his transmission popped back to gear. As he was trying to limp it back in to the pits, he was rear-ended by Mears, whose wobble collected Kasey Kahne, Danica Patrick, Martin Truex, Jr., and Carl Edwards. The resulting mess caused a red flag for obvious reasons.

At the time, Keselowski thought the culprit was a broken axle because the car started vibrating vibrantly when it popped out of gear, but that turned out not to be the case.

This race featured two red flags: the one caused by Mears hitting Keselowski's wounded car and another that came out with ten laps to go from contact between Marcos Ambrose and Kyle Larson.

Brad Keselowski now drops to seventh in the playoff-style Chase for the Sprint Cup standings after leading from his win at Talledega. Kevin Harvick is the only Chase contender below him in the points standings. Harvick's car hit a wall after contact with Matt Kenseth.