Laverty's charge to the front, from 11th position on the grid, had threatened to be compromised by an earlier incident in the race when his failed attempt to pass Rutter at Hizzy's resulted in him going off the track, only to resume directly in the path of the Ducati man. Forcing Rutter to drop positions to both Kiyonari and Laverty as he sat up, the incident was investigated by stewards, though no action would be taken against the Swan Yamaha rider.
Even so, Laverty pushed on to create a comfortable advantage heading into the penultimate lap, only for him to be caught out slightly by dust that had been kicked up on the exit of Cascades. It was the invitation Hopkins – who had just passed Easton – needed to dive up the inside at Island Bend and lead a BSB race for the first time.
Laverty recovered for second position and set about regaining the lead over the final lap. However, far from pressuring the BSB rookie into a mistake, Laverty out-braked himself at Hizzy's once more to drop behind the chasing pack.
It meant Hopkins had just enough of a gap over Easton to score his first ever Superbike victory since making his category debut back in 2009. The result also makes him the first American to win a BSB race.
Easton was on the podium once more in second, the MSS Colchester Kawasaki rider moving into the same position in the standings as a result.
A clamour to the finish line saw Shane Byrne grab third from race one winner Kiyonari by a tenth of a second, the former champion having now established an 11 point advantage in the standings.
Behind Kiyonari, Laverty was a fairly disgruntled fifth after a tumultuous day of racing, comfortably ahead of Rutter, who nonetheless enjoyed a strong run to sixth position.
Despite setting the fastest lap of the race, Jon Kirkham – who started ahead of Hopkins on the grid – could get no higher than seventh position, the Suzuki man ahead of a charging Peter Hickman, the Tyco Honda rider recording his best BSB finish in eighth.
Loris Baz and Gary Mason completed the top ten, ahead of Chris Walker, Martin Jessopp, James Westmoreland, Lowes – who slipped back to 14th but still claimed EVO honours – and finally Dan Linfoot, the Honda man recovering from an earlier off to score the final point.