Ant West held off a big late push from Maverick Vinales to win the Dutch Moto2 Grand Prix in Assen.
After qualifying in 23rd the tricky weather conditions played into the hands of the 33 year-old Australian.
The QMMF Speed Up rider managed his tyres and was faultless on his way to the win with strong passing putting him into contention as others struggled.
The win is West's first victory since his only previous win which came in the 250cc class back in 2003, also at Assen.
Maverick Vinales knuckled down to get through the wet opening laps, conditions he doesn't favour, to get into the leading pack.
Lapped back-marker Dominique Aegerter halted his run for the lead, but the Paginas Amarillas HP 40 rookie came back to battle past Mika Kallio and challenge West on the final lap, finishing just 0.318s behind.
Marc VDS rider Kallio was clear in third to complete the podium finishers aboard his Kalex.
The rain deluge before the race lead to some tyre gambles which were to play a part in the order of the race as many of the usual points scorers were not to figure.
Johann Zarco had another strong result for his AirAsia Caterham Suter team in fourth after a podium in Catalunya.
Alex DeAngelis also showed his experience in the changeable conditions to push for fifth for Tasca Racing, just ahead of another Suter, the charging Tom Luthi in sixth for Interwetten.
Julian Simon faded form a top three start to finish seventh, his first top ten finish of the season for Italtrans.
Championship leader Rabat, who crashed on the original sighting lap as the rain arrived, struggled in the wet, and was a steady eighth for Marc VDS.
Lorenzo Baldassarri also enjoyed his best finish of the season in ninth, in the top ten for the first time for Gresini.
After a huge gap Hafizh Syahrin snuck tenth from Gino Rea, who was just ahead of Marcel Schrotter's Tech 3 in eleventh and twelfth respectively.
Rea was supreme in the wet as he moved from 33rd on the grid taking his first points of the season in style for AGT REA Racing despite a run through the gravel.
Simone Corsi threw away an eleven second lead when he crashed with thirteen laps still to run. He rejoined to take the NGM Forward Racing bike to a points finish in 13th.
Taka Nakagami took 14th ahead of Louis Salom in 15th for the final point, the injured Spaniard lost the front while in the hunt for the podium places but picked up his Paginas Amarillas HP 40 to get back in the race.
Early leader Sam Lowes crashed out of second for Speed Up with sixteen laps remaining. The British rider grabbed his bike to rejoin but crashed again immediately and more spectacularly ending his race.
Also falling in the tricky conditions were Azlan Shah,Tetsuta Nagashima, Axel Pons and Sandro Cortese.
The riders who chanced a slick tyre Dominique Aegerter, Sandro Cortese, Jordi Torres, Xavier Simeon and Robin Mulhauser all failed to figure through most took to the pits to change tyres and rejoin.
AGR Team rider Jonas Folger not only made the wrong tyre choice but the received a ride through penalty for speeding when leaving the pits after his change.