Laverty would find his way through with four laps remaining, before Byrne – having dispatched of Brookes and then Westmoreland – would follow suit on lap 11 to move back up to third position.
It was too late for Laverty and Byrne to do anything about Lowes though, the youngster proving the quickest rider on the circuit in the closing stages to take the chequered flag by more than five seconds.
A full 25 points to help his burgeoning title campaign, Lowes has now ascended to third in the overall standings on 559 points, 29 points behind Byrne, whose last lap pass of Laverty earned him 20 points for second, enough to see him move back ahead of Brookes in the overall standings.
Brookes would eventually cross the line in fourth place behind Laverty, the Australian dropping five points in arrears of Byrne as a result.
Westmoreland's run to fifth place has strengthened his chances of winning the 'BSB Cup', particularly as Noriyuki Haga finished outside the top 15, while Bridewell had to contend with a slightly unsatisfying sixth place after arguably his finest ride of the season.
Meanwhile, the first Silverstone race would prove to be a disaster for pre-Showdown favourite Tommy Hill, the front row starter unable to match the pace of his rivals as he trailed in a distant seventh position. The result means he has slipped behind Lowes in the standings and is 31 points off the lead with four races remaining.
Behind him, Luca Scassa got the better of Padgetts Honda team-mate Ian Lowry for eighth, while Chris Walker rounded out the top ten. Robbin Harms, Jon Kirkham, Karl Harris, Peter Hickman and Patric Muff completed the points' paying positions.