Fernando Alonso led Toyota Gazoo Racing to a one-two finish in second practice for the 6 Hours of Spa-Francorchamps on Thursday afternoon, setting the pace in a rain-hit session interrupted by four red flags.

Heavy rain began falling in the lead-up to the start of FP2 at the Circuit de Spa-Francorchamps, and while it grew lighter through the middle of the session, it would persist until the chequered flag.

Alonso set the fastest time behind the wheel of the #8 Toyota TS050 Hybrid, recording a best lap of 2m19.483s to finish 1.3 seconds clear of Mike Conway in the sister #7 Toyota, giving the Japanese manufacturer a one-two finish.

Vitaly Petrov finished as the leading non-hybrid driver in third for SMP Racing, lapping a further half a second off Conway's time in the #11 BR Engineering BR1 AER.

Petrov, Stoffel Vandoorne and Mikhail Aleshin were left to fly the flag solo for SMP Racing in FP2 after Stephane Sarrazin crashed at Blanchimon in the damp conditions, bringing out the second of four red flags.

Following an early stoppage for a slow-moving BMW M8 GTE on-track, Sarrazin aquaplaned into the barrier on the exit of Blanchimont. While the Frenchman was unharmed, the shunt did stop proceedings for 10 minutes as the car was returned to the pits on the back of a truck.

A third red flag was called at the one-hour mark due to a shunt for Larbre Competition's Nicholas Boulle at Turn 1, causing damage to the right-rear of the #50 Ligier JS P217 Gibson.

The fourth and final red was called with 30 seconds left on the clock, caused by Pierre Thiriet in the #36 Signatech Alpine Matmut entry.

DragonSpeed headed the field in LMP2 with its #31 Oreca 07 Gibson, while Aston Martin Racing topped GTE-Pro with Marco Sorensen in the #95 Vantage AMR. Dempsey-Proton Racing took top spot in GTE-Am with the #77 Porsche 911 RSR.