Moto2: Alex de Angelis wins in rain as Marc Marquez crashes

The Spaniard's exit means the title remains undecided, although with main rival Pol Espargaro finishing down in 11th Marquez remains a heavy favourite.

The downpour that had earlier delayed the start of the race had an even more marked effect once it started. Conditions ran from treacherously wet to dry and then back in little more than 17 laps, with the havoc of the weather reflected in a massively jumbled track order.

Nowhere was that more apparent than in the form of Malaysian wildcard Hafizh Syahrin who, from 27th on the grid, set a string of fastest laps and had soon moved into a shock lead.

He began pulling away too, but a moment at Turn 1 marked the end of his spell at the front, allowing a trio of chasing riders - de Angelis among them - to close.

Syahrin held on to clinch fourth, but was not a feature of the three-way lead battle that raged over the final laps.

De Angelis held the advantage but with three laps of the official distance to run first Gino Rea and then Anthony West moved ahead. The trio had already been swapping places at the front throughout the opening 15 laps.

As conditions steadily worsened however the race was halted, with Forward rider de Angelis earning the victory as the lap was counted back. West claimed second for QMMF, fractions ahead of Gresini's Rea, as both secured their first ever Moto2 podiums.

While the trio duelled, several other riders had trouble simply staying on the circuit.

Marquez was among them, falling while trying to resist Andrea Iannone four laps from what was the eventual finish.

At the time Espargaro was 13th, meaning that even as Marquez despaired by the side of the circuit he was heading for the title.

Espargaro, helped by several other riders exiting, made his way up to 11th by the finish however. The extra points gained keep the title race alive until at least Australia next weekend, although Marquez needs just two more to secure the crown.

Iannone ended the race sixth, behind Julian Simon, but ahead of Mika Kallio, Bradley Smith and Dominique Aegereter.

Esteve Rabat meanwhile claimed 10th ahead of Pons team-mate Espargaro.

Results - 15 laps (red flag):

Pos  Rider                 Team/Bike                 Time/Gap
 1.  Alex de Angelis       Forward FTR             36m57.793s
 2.  Anthony West          QMMF Speed Up             + 0.710s
 3.  Gino Rea              Gresini Suter             + 1.363s
 4.  Hafizh Syahrin        Petronas FTR              + 2.941s
 5.  Julian Simon          Avintia Suter             + 7.583s
 6.  Andrea Iannone        Speed Master Speed Up    + 10.062s
 7.  Mika Kallio           Marc VDS Kalex           + 23.078s
 8.  Bradley Smith         Tech 3                   + 26.957s
 9.  Dominique Aegerter    Technomag-CIP Suter      + 30.063s
10.  Esteve Rabat          Pons Kalex               + 31.514s
11.  Pol Espargaro         Pons Kalex               + 31.746s
12.  Scott Redding         Marc VDS Kalex           + 37.108s
13.  Toni Elias            Italtrans Kalex          + 38.627s
14.  Axel Pons             Pons Kalex               + 39.095s
15.  Ricard Cardus         Arguinano AJR            + 40.686s
16.  Yuki Takahashi        Forward FTR              + 40.757s
17.  Tomoyoshi Koyama      Technomag-CIP Suter      + 41.859s
18.  Marcel Schrotter      SAG Bimota               + 46.760s
19.  Jesko Raffin          Switzerland Kalex      + 1m10.712s
20.  Elena Rosell          QMMF Speed Up          + 1m17.807s
21.  Marco Colandrea       SAG FTR                + 1m19.320s
22.  Ratthapark Wilairot   Gresini Suter          + 1m27.281s
23.  Simone Corsi          Ioda FTR               + 1m41.865s

Retirements:

     Thomas Luthi          Paddock Suter              14 laps
     Mike di Meglio        Kiefer Kalex               14 laps
     Marc Marquez          Monlau Suter               12 laps
     Nicolas Terol         Aspar Suter                12 laps
     Jordi Torres          Aspar Suter                12 laps
     Eric Granado          JIR Motobi                  6 laps
     Takaaki Nakagami      Italtrans Kalex             2 laps
     Johann Zarco          JIR Motobi                  0 laps
     Xavier Simeon         Tech 3                      0 laps
     Alessandro Andreozzi  Speed Master Speed Up          DSQ