Brad Keselowski showed the way during Friday evening's final Happy Hour practice session in advance of Sunday night's Bojangles' Southern 500 at Darlington Raceway.

Keselowski, the 2012 NASCAR Sprint Cup Series champion, wheeled his No. 2 Team Penske Ford to a fast lap of 175.880 miles per hour at the 1.33-mile South Carolina track.

Second-fast at 175.729 mph was Greg Biffle, who earlier topped the speed charts in the day's opening practice in his Roush Fenway Racing Ford. Then it was Kurt Busch at 175.723 mph in the first of the four Stewart-Haas Racing Chevrolets. Richard Childress Racing teammates Paul Menard and Austin Dillon completed the top five, with Danica Patrick ninth and Dale Earnhardt Jr. 15th.

In the final 15 minutes of the 1 hour, 55-minute session, many drivers switched from race trim to qualifying trim, which jumbled the speed charts considerably in the late going.

About halfway through Happy Hour, Kyle Busch had a wallbanger in Turn 2 with his Joe Gibbs Racing Toyota and had to go to a backup car after bending sheetmetal and suspension parts.

Busch comes into the race 29th in points and must be 30th or better after the final Sprint Cup regular season race next week at Richmond International Raceway to advance to the Chase for the NASCAR Sprint Cup. The good news for Busch is that he is 46 points ahead of 31st place, and barring two disastrous outings in a row should easily cruise into the Chase.

With about 20 minutes left in Happy Hour, Busch got his backup on track, and he finished the session in 35th place.

The only on-track activity for the Sprint Cup teams on Saturday will be qualifying, which is scheduled for 1:45 p.m. ET.

Take a look at the full results from final practice: