Kenseth's No. 20 crew chief Jason Ratcliff was originally suspended for six races for using connecting rods at Kansas that did not meet the minimum weight, but that penalty was later reduced to one race -- Saturday's Southern 500.
Wally Brown filled in for Ratcliff and collected his first Sprint Cup victory at Darlington as Kenseth chased down and passed Busch with 13 laps to go.
Busch had led for 265 of 367 laps but sustained a cut right-rear tire within the 20 final laps.
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