Gaughan won for the first time in the series, breaking through in his 98th career start.
Gaughan noted that he made his fair share of mistakes along the way - pretty much every driver did in challenging driving conditions -- and thanked his crew for helping him rally to win.
"I booted this race twice, and thank you to these boys right here," Gaughan said. "They still believed in me."
Alex Tagliani was second, followed by Kevin O'Connell, Chase Elliott and J.J. Yeley as NASCAR drivers got a rare opportunity to race in the rain. It was a disappointing finish for Tagliani, who led in the closing stages of regulation but ran out of gas after a late caution flag came out.
It was the third time in Nationwide history that grooved rain tires have been used in a race; the previous two were in Montreal. NASCAR only uses rain tires on road courses, not on oval tracks.
The rain added a tense new dimension to racing at Road America, a four-mile road course where the Nationwide Series already had shown an ability to put on a good show.
Tagliani was leading when a caution flag came out with just over a lap left in the race, ensuring the green-white-checkered finish - NASCAR's version of overtime, as officials attempt to ensure that the race finishes under green. Then Tagliani's car came to a sudden stop under caution, as he ran out of gas.
That handed the lead to Gaughan, who had been chasing Tagliani down in the closing laps of regulation.
Gaughan then lost the lead to Elliott almost immediately on the restart, and Elliott - the 18-year-old son of NASCAR icon Bill Elliott - suddenly appeared headed to victory.
But Gaughan got back around Elliott, retaking the lead with just over a lap to go. Gaughan held off O'Connell for most of the last lap, then withstood a late charge from Tagliani, who refueled his car and nearly charged all the way back to the lead.
"It was pretty intense," Tagliani said. "The wet was tricky, but obviously we were good."
The race started about an hour late, as NASCAR officials waited for a slightly damp track to dry out; the series has grooved rain tires available for racing in the rain, but those tires are designed for full wet conditions.
Officials determined that the light drizzle before the race was too wet for drivers to tackle on slick tires - and not wet enough for them to use rain tires, which wear out quickly when they are used in dry or semi-dry conditions. Other racing series that race in the rain more frequently have intermediate tires available for partially wet conditions, and allow crews to decide for themselves what kind of tires to use.
Slightly heavier rain then began to fall just before the race's halfway mark, causing the race to go under caution for a few laps before instructing teams to put on rain tires - resulting in a rare test of NASCAR drivers' skills in the rain.
"It was ridiculous," Elliott said. "It really was. It was a handful. It wasn't all that bad until the rain started to go away and the sun started to come out, because you couldn't see."
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