Sandro Cortese took his first grand prix pole position during Friday's 125cc qualifying session at Assen.
Eighth on Thursday, the Ajo Interwetten rider snatched the top spot by just 0.011sec on the very last lap of qualifying, marking his first front row start of the year.
2009 is Cortese's fifth season in grand prix racing and the German took his first and only podium so far with third in the rain-shortened Qatar night race.
World championship leader and Thursday pace setter Julian Simon will start second with fellow Aprilia riders Nicolas Terol and Stefan Bradl completing the front row.
Simon's Aspar team-mate Bradley Smith was fifth, but just 0.282sec from pole. Smith will start Saturday's race just 1.5 points behind Simon in the championship.
Qualifying - Assen:
1. Cortese (Derbi)
2. Simon (Aprilia) +0.011sec
3. Terol (Aprilia) +0.214sec
4. Bradl (Aprilia) +0.249sec
5. Smith (Aprilia) +0.282sec
6. Iannone (Aprilia) +0.481sec
7. Corsi (Aprilia) +0.526sec
8. Espargaro (Derbi) +0.633sec
9. Gadea (Aprilia) +0.695sec
10. Marquez (KTM) +0.734sec
13. Webb (Aprilia) +0.848sec
17. Redding (Aprilia) +1.657sec