Nonetheless, far from settling for second, Crutchlow began to reapply the pressure during the closing stages, slicing the gap down to less than a second in what was destined to be a grandstand finish.
As it happens, Crutchlow's hopes of overhauling Lascorz were prevented by a red flag, deployed after an oil spillage at Lycee caused three accidents in quick succession.
With no time to restart the race, Lascorz was declared the race winner, signalling a maiden win for the Provec Motocard team, as well as a first triumph for Kawasaki since Fabien Foret won at Phillip Island in 2007.
Crutchlow had to settle for second to add 20 vital points onto his tally, giving him a 19 point buffer over Laverty, who defied a damaged bike to claw his way back up to 13th for three points of his own. It means Crutchlow needs just a top ten finish at Portugal to be crowned the champion.
Despite his rival's win, Kenan Sofuoglu continues to keep Lascorz at bay in the overall standings after finishing on the podium for the fifth time this season.
Almost 15 seconds further back, the early stoppage had also curtailed a thrilling fight for fourth position between the three Hondas of Andrew Pitt, Mark Aitchison and Anthony West, as well as the Kawasaki of Katsuaki Fujiwara.
Never separated by more than a second, all four jostled for the position, particularly on the run down to Adelaide as they capitalised on one another's slipstream. Eventually, however, it was Stiggy's West who would emerge in front – having started a lowly 16th -, ahead of Aitchison on the Althea machine and reigning champion Pitt on the Ten Kate bike. Fujiwara had to make do with seventh.
In a race of attrition that would see just 16 riders classified at the finish, Massimo Roccoli was eighth, from returnee Matthieu Lagrive, while Michele Pirro recovered to tenth after a terrible start from fifth on the grid had seen him outside the points early on.
Local rider Olivier Four was 11th, ahead of Miguel Praia, the recovering Laverty, Kev Coghlan and Arie Vos.