Jerez winner Pol Espargaro continued his front-running form during Friday practice for the French 125cc Grand Prix at Le Mans.

The Tuenti Derbi rider enjoyed a lead of over half a second from countryman Marc Marquez, who won the opening round in Qatar but sustained a dislocated shoulder in an early tumble on home asphalt in Spain.

Ajo's Sandro Cortese made it an all-Derbi top three, while a dark day for reigning champion's Aspar Aprilia saw both its riders stop out on track with technical problems.

Bradley Smith, who has battled a lack of engine performance at the opening two rounds, suffered a terminal technical failure after just nine laps, leaving the Englishman in 18th.

Team-mate and 2010 title leader Nicolas Terol, presently seven points clear of Espargaro, lasted until almost the end of the session before pulling off track, having already set the fourth fastest time from his 22 laps.

Friday practice - Le Mans:

1. Espargaro (Derbi) 1m 43.908s
2. Marquez (Derbi) +0.522s
3. Cortese (Derbi) +0.761s
4. Terol (Aprilia) +1.196s
5. Zarco (Aprilia) +1.549s
6. Krummenacher (Aprilia) +1.663s
7. Koyama (Aprilia) +1.728s
8. Rabat (Aprilia) +1.882s
9. Vazquez (Derbi) +1.918s
10. Webb (Aprilia) +1.973s

18. Smith (Aprilia) +3.779s