3rd Marco Melandri – 1998 Dutch 125 GP at 15 years and 324 days
The Ravenna-born rider was the first under-16 to win a GP, which he did with the Matteoni team’s Honda, beating Kazuto Sakata by just 28 thousandths of a second. He left the World Championship with 22 victories and the 2002 250 title under his belt, before going on to secure another 22 Superbike wins.
2nd Scott Redding – 2008 British 125 GP at 15 years and 170 days old
The Briton's only 125 win with the Aprilia Esponsorama coincided with Marc Marquez's first podium finish. Redding went on to win three Moto2 races, as well as winning the British Superbike with Ducati, with which he finished runner-up the following year.
1st Can Oncu – 2018 Valencian Community Moto3 GP at 15 years and 115 days
The Turk won the Red Bull Rookies Cup in 2018, as a result of which he got to make his debut in Valencia with Red Bull KTM Ajo. He repaid them by winning his debut race for them by 4 seconds, a feat he failed to achieve again the following year. He has been competing at the Supersport World Championship since 2020.
Missing from this list are legends such as Valentino Rossi and Marc Marquez, who won their first GPs at the age of 17 and remained loyal to Brembo for the rest of their careers.