Jorge Martin thwarted world champion Francesco Bagnaia to land Saturday's German MotoGP sprint race.
Jack Miller for KTM completed the podium.
Bagnaia's second at the Sachsenring kept him atop the world championships standings ahead of Sunday's seventh race of the season.
Martin, whose only previous victory in the premier class came at the Styrian Grand Prix in his rookie 2021 season, was rewarded for his efforts by leapfrogging Marco Bezzecchi into second in the riders standings, 21 points adrift.
Pole-sitter Bagnaia fought off Miller to keep the lead at the start but a mistake under pressure let the Australian through to take command on the factory KTM.
Around the tight and narrow circuit Martin then nipped past Miller and Bagnaia to take control on lap four of 15, the Ducati-Pramac rider pulling well clear to coast home by 2.468 seconds.
"I really enjoyed those laps, I was on the limit," said the 25-year-old Spanish sprint winner.
"I tried to keep the distance with 'Pecco' (Bagnaia) -- hopefully tomorrow I can fight for victory," added the Ducati-Pramac rider.
Bagnaia commented: "I enjoyed the battle with Jack, then Jorge who was fastest today.
"I have to accept second place, now we move on to tomorrow."
Bezzecchi, who had to settle for seventh on Saturday, dropped to third overall on 113 points.
As Martin celebrated, one of his more celebrated grid rivals - six-time MotoGP world champion Marc Marquez - was reflecting on the end of an astonishing run at the Sachensering, where he has won the last 11 Grand Prix he has lined up in across all categories from 2010.