Second was enough to move Cortese into a near-unassailable position in the championship, after his closest rival Maverick Vinales' Avintia FTR-Honda suffered a seized engine on the warm-up lap and was unable to compete.
Cortese tried to take full advantage of his absence and several times hit the front and attempted to lift the pace, but he was not able to break free from a lead pack that never consisted of less than seven riders and was rarely separated by more than one second.
The result was a constantly changing order, with positions changing ceaselessly throughout the 20-lap contest.
With two laps to run Salom hit the front for the first time, while Cortese suddenly found himself bumped down to fifth, having led for much of the middle section.
The German fought back and on the final lap cut by Salom to retake the lead, only to get demoted once more, with Jonas Folger (Aspar Kalex KTM) also coming by into second.
Ultimately that proved too much to overcome, and while Cortese picked off Folger on the back straight, where the KTM proved mighty, he was not able to bridge back to Salom before the chequered flag fell.
Folger took third ahead of Cortese's team-mate Danny Kent, who moved from eighth to first in the space of one lap just after the race's halfway mark.
Kent lost touch with the lead trio while duelling with Efren Vazquez in the final laps, but despite being run wide by the Spaniard was able to hang on to claim fourth.
Vazquez sealed fifth, while Louis Rossi - another rider who enjoyed a spell at the front – split Monlau Honda team-mates Alex Rins and Miguel Oliveira, who finished sixth and eighth respectively.
Zulfahmi Khairuddin also led in the early stages, but dropped to the back of the front pack as the race wore on and then crashed out with six laps to run.
- Jonas Folger