Jonas Folger made a bright start to the TT Assen weekend by topping a first practice session which was disrupted by light rain.
Conditions on Thursday morning were cold and spots of rain began to fall within six minutes of the session getting underway, with only a handful of riders having set a time, Hector Faubel the quickest of them.
Once the riders re-emerged, several took turns at the top of the timesheets, including Britain's Danny Webb for a prolonged spell, but eventually it was Folger who was the fastest man when the rain returned with five minutes to go.
The German who claimed his first ever Grand Prix win two weeks ago at Silverstone seems to have been given a confidence boost by that victory, and he led the way with a 1:47.191.
Compatriot Sandro Cortese was 0.387s behind in second ahead of Maverick Vinales, with championship leader Nicolas Terol unaccustomed to be as low as fourth. Bankia Aspar teammate Hector Faubel was fifth ahead of Frenchman Alexis Masbou who impressed on the Caretta Technology KTM.
Luigi Morciano was another unfamiliar name at the top of the leader board with the Italian ending the session in seventh ahead of Luis Salom who will look to build on his career-best fourth place in the British Grand Prix.
The Brits performed well at their home event and that form continued here with Danny Kent and Danny Webb going ninth and tenth. Webb appeared to get up to speed quicker than anyone else in the slippery conditions but was one of six riders to slide off track when the rain returned late on.
Taylor Mackenzie was another to fall and ended the session in 28th. The Scottish teenager will not take part in this afternoon's session as he goes off to take an A-Level exam in Product Design. Harry Stafford will hope to be involved after missing this morning's session altogether.
Free Practice 1 Times:
| Pos | Rider | Nat | Team | FP1 | Gap |
| 1 | Jonas Folger | GER | Red Bull Ajo MotorSport | 1:47.191 | |
| 2 | Sandro Cortese | GER | Intact-Racing Team Germany | 1:47.578 | +0.387 |
| 3 | Maverick Vinales | SPA | Blusens by Paris Hilton Racing | 1:48.147 | +0.956 |
| 4 | Nicolas Terol | SPA | Bankia Aspar Team | 1:48.847 | +1.656 |
| 5 | Hector Faubel | SPA | Bankia Aspar Team | 1:49.115 | +1.924 |
| 6 | Alexis Masbou | FRA | Caretta Technology | 1:49.129 | +1.938 |
| 7 | Luigi Morciano | ITA | Team Italia FMI | 1:49.424 | +2.233 |
| 8 | Luis Salom | SPA | RW Racing GP | 1:49.908 | +2.717 |
| 9 | Danny Kent | GBR | Red Bull Ajo MotorSport | 1:49.976 | +2.785 |
| 10 | Danny Webb | GBR | Mahindra Racing | 1:49.979 | +2.788 |
| 11 | Sturla Fagerhaug | NOR | WTR-Ten10 Racing | 1:50.109 | +2.918 |
| 12 | Marcel Schrotter | GER | Mahindra Racing | 1:50.119 | +2.928 |
| 13 | Alberto Moncayo | SPA | AndalucÃa Banca Civica | 1:50.275 | +3.084 |
| 14 | Luca Gruenwald | GER | Freudenberg Racing Team | 1:50.391 | +3.200 |
| 15 | Bryan Schouten | NED | Dutch Racing Team | 1:50.719 | +3.528 |
| 16 | Simone Grotzkyj | ITA | Phonica Racing | 1:50.762 | +3.571 |
| 17 | Johann Zarco | FRA | Avant-AirAsia-Ajo | 1:50.931 | +3.740 |
| 18 | Sergio Gadea | SPA | Blusens by Paris Hilton Racing | 1:50.993 | +3.802 |
| 19 | Peter Sebestyen | HUN | Caretta Technology | 1:51.147 | +3.956 |
| 20 | Jakub Kornfeil | CZE | Ongetta-Centro-Seta | 1:51.255 | +4.064 |
| 21 | Jerry van de Bunt | NED | Jerrys Racing Team | 1:51.466 | +4.275 |
| 22 | Giulian Pedone | SWI | Phonica Racing | 1:51.583 | +4.392 |
| 23 | Jasper Iwema | NED | Ongetta-Abbink-Metaal | 1:51.689 | +4.498 |
| 24 | Niklas Ajo | FIN | TT Motion Events Racing | 1:51.832 | +4.641 |
| 25 | Efren Vazquez | SPA | Avant-AirAsia-Ajo | 1:52.315 | +5.124 |
| 26 | Adrian Martin | SPA | Bankia Aspar Team | 1:52.701 | +5.510 |
| 27 | Louis Rossi | FRA | Matteoni Racing | 1:52.891 | +5.700 |
| 28 | Taylor Mackenzie | GBR | Phonica Racing | 1:53.060 | +5.869 |
| 29 | Ernst Dubbink | NED | RV Racing Team | 1:53.259 | +6.068 |
| 30 | Francesco Mauriello | ITA | WTR-Ten10 Racing | 1:53.304 | +6.113 |
| 31 | Zulfahmi Khairuddin | MAL | AirAsia-Sic-Ajo | 1:53.802 | +6.611 |
| 32 | Josep Rodriguez | SPA | AndalucÃa Banca Civica | 1:53.816 | +6.625 |
| 33 | Joan Perello | SPA | Matteoni Racing | 1:54.201 | +7.010 |
| Provisional 107% Time: 1:54.694 | |||||
| NC | Alessandro Tonucci | ITA | Team Italia FMI | 1:56.449 | +9.258 |
| NC | Thomas van Leeuwen | NED | Racing Team Van Leeuwen | 1:57.462 | +10.271 |
| NC | Harry Stafford | GBR | Ongetta-Centro-Seta | No Time | |
