It would be the decisive move of the race, Ellison taking the opportunity to blunt his rivals' response by pumping in a series of quick laps to put air between himself and Easton, who followed Ellison through on the same lap at the Esses.
Indeed, Ellison was untouchable, Easton's attempts at catching him again being stymied by the constant attentions of Walker, who maintained a presence in third for the remainder of the race.
It meant Ellison would come home a comfortable 2.5secs up on Easton to be crowned a BSB winner for the first time, ahead of Easton, scoring his second podium of the day, and Walker, who too is making his first appearance on the BSB podium for some time.
Although they fell away from the fight for the podium, the tussle for fourth was equally tense, with Richards – who dropped to sixth – catching and passing both Da Costa and Andrews, only for the latter to snatch the position back with a last gasp move on the final corner. Fourth represents the MSS Colchester Kawasaki rider's best ever BSB result.
Having lapped at the pace of the leaders briefly, Da Costa dropped back rapidly in the final few laps to go from fourth to 11th, being caught and passed by Ian Lowry and Cup winner Gary Mason, who crossed the line sixth and seventh.
Buildbase Kawasaki produced a welcome double top ten with John Laverty ahead of Tristan Palmer in eighth and ninth, while Graeme Gowland completed a good day for Rob Mac Yamaha to claim tenth.
Camier, meanwhile, put in an immense charge to rise up from 25th position to finish 12th and snatch three points for himself.
Elsewhere, having missed the first race following his part in the accident that involved Guintoli, Joshua Brookes would crash out of contention on lap eight, while Karl Harris was also out of the points after hitting problems on the final lap of the race.