Roberto Merhi goes fastest for Prema in second practice for Formula 3 Masters

The Mercedes-supported driver, who is virtually certain to clinch the FIA Formula 3 International Trophy this weekend and also leads the Euro Series standings, set the pace in 1m31.904s.

The man who came closest to usurping the Spaniard was Signature's Marco Wittmann, the leading driver using Volkswagen power and 0.311s slower than Merhi.

Wittmann is a distant 75 points adrift of Merhi in the Trophy standings, and required his rival not to score this weekend in order to remain in the title fight at the series' next round at Macau in November.

"[The Masters] is one of the most important F3 races in the world, and a Spaniard has never won it, so that gives me a lot of motivation to try and be the first," said Merhi. "Besides winning the race itself, I want to leave having sewn up FIA F3 Trophy. In principle, save a catastrophe, this should present no problem, as I have only to score one point, and if not Wittmann would still have to win the race [in order to prolong the fight]."

Dutchman Nigel Melker, who lives around 90 minutes south of Zandvoort, was third fastest in a session affected by worsening weather conditions. The Mucke racer has scored three Euro Series wins this season and is keen to reward his home support with a repeat of his May's Euro Series victory at the circuit.

"I am reasonably happy with third," said Melker. "The conditions can change quite quickly here because we're on the coast. In this second session it started out dry and then the rain came after about 15 minutes. We've made a few changes since the Euro Series round on the car, but nothing too serious."

Merhi's Prema team-mate and Euro Series title rival Daniel Juncadella was fourth ahead of Felix Rosenqvist (Mucke). In an eventful session, Swede Rosenqvist caused the second appearance of the red flags after crashing at Master corner - Signature's Carlos Munoz caused the initial stoppage.

Rain intensified during the clear-up procedure, and none of the 16-car field were able to improve their lap times during the second half of the session.

Rupert Svendsen-Cook (Carlin), who set the pace in the first session, was again the best of the British series runners in seventh.

Pos  Driver                Team           Car            Time       Gap
 1.  Roberto Merhi         Prema        Dallara-Merc  1m31.904s
 2.  Marco Wittmann        Signature    Dallara-VW    1m32.215s  + 0.311s
 3.  Nigel Melker          Mucke        Dallara-Merc  1m32.564s  + 0.660s
 4.  Daniel Juncadella     Prema        Dallara-Merc  1m32.700s  + 0.796s
 5.  Felix Rosenqvist      Mucke        Dallara-Merc  1m32.937s  + 1.033s
 6.  Daniel Abt            Signature    Dallara-VW    1m33.056s  + 1.152s
 7.  Rupert Svendsen-Cook  Carlin       Dallara-VW    1m33.069s  + 1.165s
 8.  Laurens Vanthoor      Signature    Dallara-VW    1m33.609s  + 1.705s
 9.  Carlos Munoz          Signature    Dallara-VW    1m33.627s  + 1.723s
10.  Jazeman Jaafar        Carlin       Dallara-VW    1m34.002s  + 2.098s
11.  Carlos Huertas        Carlin       Dallara-VW    1m34.065s  + 2.161s
12.  Pipo Derani           Prema        Dallara-Merc  1m34.103s  + 2.199s
13.  Lucas Foresti         Mucke        Dallara-Merc  1m34.104s  + 2.200s
14.  Kimiya Sato           Motopark     Dallara-VW    1m34.694s  + 2.790s
15.  Jimmy Eriksson        Motopark     Dallara-VW    1m34.997s  + 3.093s
16.  Kevin Magnussen       Carlin       Dallara-VW    1m35.239s  + 3.335s