Defending British Touring Car champion Ash Sutton has strengthened his lead at the top of the championship after snatching the race two victory away from Colin Turkington after an epic final lap duel at Knockhill.

Team BMW's Turkington led virtually every corner of what proved to be an incident packed second race from pole position, but was ultimately unable to keep a rejuvenated Sutton at bay following an enthralling near race-long battle.

With Sutton moving up to second on lap nine of the race, the Laser Tools Racing driver made light work of closing the gap to the race leading BMW of Turkington.

For much of the duel, Turkington was inch perfect in the defence of his race lead. However, following a late safety car after a collision between compatriots Rory Butcher and Aiden Moffat, Sutton ramped up the pressure on Turkington, which eventually took its toll on the Team BMW driver midway through the final lap.

A slight error from Turkington saw the BMW 330i M Sport slip off the racing line and into gravel on the exit of the Chicane. That was enough to hand Sutton the lead and a clear route to his third win of the year.

Turkington managed to hang onto second ahead of MB Motorsport's Jake Hill, who made a return to the podium order in third.

BTC Racing's Josh Cook finished in fourth ahead of home hero Gordon Shedden, who rose further up the order on the soft tyre from eighth to fifth.

Tom Ingram scored further points in sixth position, with Senna Proctor falling from second in race one to seventh in race.

Rory Butcher and Aiden Moffat's late clash saw two-time champion Jason Plato rise up the order with an eighth place finish ahead of Stephen Jelley and Carl Boardley in ninth and tenth.

Jelley and Plato will start the reverse grid final race from the front row after Jelley's finishing position was picked in the reverse grid draw.