Edwards, who missed qualifying at Memphis Motorsports Park because of practice for today's Sprint Cup race in Atlanta, started 34th in his No. 60 Ford. But he made an early stop for tires and gained ground quickly, taking the lead from Mike Bliss on the 69th lap. He never trailed after that.
Reutimann kept his Toyota on Edwards' rear bumper for the final two laps, but couldn't overtake him for the lead.
Edwards pulled within 116 points of series leader Clint Bowyer, who finished 16th. There are three races remaining.
Kenny Wallace finished third, his best series finish since 2005. He was followed by Austin Dillon, grandson of NASCAR team owner Richard Childress who was making just his second Nationwide start. Joey Logano finished fifth and Chase Miller sixth, the only other drivers on the lead lap.
Edwards and the lead pack held out to the last second on a round of green flag pit stops that started on the 92nd lap, and put the field a lap down at the halfway point of the race when Bowyer spun on the track, bringing out one of eight cautions. It was much cleaner than a year ago, when the yellow flag came out 25 times.
TRUCKS: In Hampton, Ga., Ryan Newman passed Ron Hornaday in Turn 2 on the last lap at Atlanta Motor Speedway to win the E-Z-Go 200 in his first Truck Series start.
Newman and Hornaday, both driving for Kevin Harvick Inc., traded the lead twice in the final eight laps. The two raced side-by-side for a lap, with Hornaday coming out in front on the next-to-last lap.
Newman then grabbed it back, and Hornaday, locked in a battle for the series championship, couldn't afford to push the issue.
Hornaday, who started the day trailing Johnny Benson by 65 points in the standings, trimmed the lead to 31 with three races to go. A victory would have given Hornaday an extra 10 points.
Benson salvaged what could have been a disastrous points day by rallying for a seventh-place finish.