Jonas, who represents the Husqvarna plant team this season, was fifth in the MXGP free practice, but he showed the best time in the second practice.
Slovenian Tim Gayser was the fastest in the qualification, losing 41,892 seconds to Jonas.
The second was the Frenchman Roman Fever, 8.724 seconds behind Guyers, and the third place was taken by the Spaniard Rubens Fernandes, 13.753 seconds behind the Slovenian athlete.
In the overall standings after 11 stages, Gayser is the convincing leader with 485 points, Jeremy Siever from Switzerland is 384 points, and Horch Prado from Spain is 366 points ahead of France Maxim Reno. Jonas has accumulated 250 points and maintains the eighth position.
The best in the MX2 class was the Frenchman Tom Vials, 7,464 seconds ahead of the Belgian driver Jago Gertz.
Latvian athletes did not start in this class.
In the overall standings of the championship, Vials Gertsam concedes eight points.