CRG factory driver Pedro Hiltbrand and VDK's Victor Martins became the 2016 CIK-FIA OK and OKJ world champions respectively at Bahrain.
Hiltbrand, 20, took his third major CIK-FIA title of the season as he also won the OK European Championship and the KZ2 International Super Cup.
Smolyar and Hiltbrand win pre-finals 1 and 2
Alexandr Smolyar grabbed pole position for the main race after winning the first of two pre-finals.
Starting on the second row, Smolyar was quickly up to second, taking advantage of leader Karol Basz running wide and dropping to ninth.
The Russian soon put pressure on Lorenzo Travisanutto and made a move on the Italian with Noah Milell also going through.
Although Smolyar was never able to pull away and was even passed by Milell temporarily, he crossed the line first with the latter settling for third as the recovering Basz fought his way up to second.
Hiltbrand took the lead in the beginning of the second pre-final and led most of the race, only to run wide in the end and allow CRG teammate Felice Tiene through.
However, the 2012 champion received a post-race time penalty and was only classified 10th.
The final result was still a CRG 1-2-3 in the order of Hiltbrand, Hannes Janker and Paavo Tonteri.
Hiltbrand beats Basz to title in main race
Despite starting on the outside line of the front row, Hiltbrand took the lead off the line with Basz soon also passing Smolyar.
The Russian dropped behind Janker on Lap 3 before running off track and retiring.
At the front, Hiltbrand continued to lead but Basz was demoted by youngsters Christian Lundgaard and Paavo Tonteri.
The Pole spent three laps in fourth before he started to fight back, soon running second again.
He then claimed the lead from Hiltbrand but he could not pull away either and a counterattack from the latter saw the duo go side-by-side, with Basz running over the kerbs and dropping out of the top five.
Hiltbrand had a comfortable lead for the rest of the race and cruised to the finish with Basz impressively recovering to second.
Tiene also had a strong late-race charge to take third from CRG teammates Tonteri and Janker.
Tom Joyner completed a near-perfect race for the Italian squad as he brought a fifth CRG kart into the top six.
Lundgaard, second before Basz passed him, was taken out by Tiene on the main straight, forcing the 15-year-old Dane to retire.
OK class top 10:
|Kosmic Racing Dept||+1.365s|
|Kosmic Racing Dept||+3.996s|
|8||Lorenzo Travisanutto||Ward Racing||+4.353s|
|9||Jean-Baptiste Simmenaur||Tony Kart Racing Team||+4.870s|
|10||Ulysse De Pauw||Kosmic Racing Dept||+5.302s|
Vidales and Martins top OKJ pre-finals
Tony Kart's David Vidales was a dominant force in the early stages of the OKJ event as the 14-year-old was quickest in qualifying and was in the top two in four of his five heats.
That allowed him to start the first pre-final from pole as well and, even though he was passed by Gianluca De Castro Petecof, he fought back to win.
The Brazilian rookie took second, closely followed by front-row starter Hampus Eriksson, brother of F1 driver Marcus, and Theo Pourchaire.
Two-time European championship race winner Martins won the second pre-final in similar fashion, converting his pole position into a victory after temporarily dropping to second behind Fin Kenneally.
Martins takes advantage of chaos to clinch title
Vidales led Lap 1 of the final but he could not hold on to first for long as De Castro Petecof went past the Tony Kart driver.
However, both Martins and Vidales overtook him next time around with the Frenchman heading the field and De Castro Petecof dropped behind several other karts on the same lap.
On Lap 6, Vidales made a move on Martins, forcing the latter slightly on the kerbs, which dropped him to fifth.
However, Vidales ended up losing his lead in the same way a lap later as Kenneally and Pourchaire passed him at the same turn and made contact, which cost the pole-sitter more positions.
Kenneally in turn then lost his lead to Martins as the Frenchman recovered in no time and quickly pulled away when he was the leader again.
His main rival Vidales also fought his way back up to second with five laps to go but couldn't take the fight to Martins and settled for second.
Pourchaire completed the podium, followed by Ivan Shvetsov and De Castro Petecof.
Kenneally ended up only 11th, dropping out of victory contention soon after he lost his lead.
Jack Doohan, son of motorcycle legend Mick, finished 23rd despite running as high as 10th after the start.
Noah Watt, one of the protagonists of the season, failed to start in the second pre-final and couldn't qualify for the main race as a result.
OK class top 10:
|Tony Kart Racing Team||+2.312s|
|3||Theo Pourchaire||Kosmic Racing Dept||+6.363s|
|4||Ivan Shvetsov||Ward Racing||+6.405s|
|5||Guanluca De Castro Petecov||CRG||+6.835s|
|6||Oscar Piastri||Ricky Flynn Motorsport||+6.999s|
|7||Kiern Jewiss||Forza Racing||+7.880s|
|8||Pavel Bulantsev||Ward Racing||+8.420s|
|9||Charles Milesi||Tony Kart Racing Team||+8.505s|