Despite taking a podium in the opening race in Spain, Jack’s team-mate George Russell clinched the title with a round to spare.
Jack has now set his sights on finishing the season on a high note in Abu Dhabi in November and cementing his runners-up spot in the series.
The weekend in Jerez began brightly for the 22-year-old Brit as he was second on the timesheets in Friday’s practice session.
And Jack looked set for a third pole position of the season in qualifying, only to be pipped by 0.169s by team-mate Nirei Fukuzumi.
In race one, Jack made a solid start before compatriot Russell barged his way through at turn two leaving Jack to battle hard to keep his podium spot.
Race two was frustrating for the ART man as he was on the receiving end of another lunge from Russell which bumped him down to sixth place.
Jack Aitken (ART, #1)
2nd – 140 points – 13/15 races completed
“I’m gutted to have had the weekend we did especially after starting so strongly in practice and nearly taking pole position in qualifying. There are positives to take forward and lots of things have been learned. We have one more round to go in Abu Dhabi and I’ll be going for a pair of wins as always.”