Mark Webber set the pace in the opening practice session for this weekend's European Grand Prix at Valencia.
The Australian posted a time of 1m40.597s to outpace Renault's Vitaly Petrov by nearly a full second in a session that was mostly incident-free.
Local hero Fernando Alonso was third fastest in the Ferrari, with Lewis Hamilton in fourth but already over a second behind the Red Bull of Webber. Nick Heidfeld completed the top five in the second Renault.
Championship leader Sebastian Vettel had a low-key start to the weekend, the German finishing down in 16th position, over 2.5 seconds off his team-mate's pace.
Force India's reserve Nico Hulkenberg was the early pace-setter during a session which saw very few drivers complete a timed lap in the first half hour.
The German's day, however, ended early after making contact with the wall at Turn 12 after losing the rear of his car under braking. The left side of Hulkenberg's car was clearly damaged, and he was forced to sit out the rest of the session, having completed just six laps.
Pastor Maldonado and Jaime Alguersuari relegated Hulkenberg down the order right after the half-hour mark, the Williams driver jumping to the top of the times only to be outpaced by the Mercedes of Schumacher 37 minutes into the session.
Massa jumped to the top just a minute later, posting a 1m42.154s, but team-mate Alonso went even quicker and became the first man to lap in the 1m41s moments later.
The Spanish driver stayed as quickest until Webber jumped onto the track to stop the clock at 1m40.597s with 37 minutes left, the Australian improving even further on his 11th lap of the day just a couple of minutes later.
A spin by Timo Glock in the dying moments of the session meant there were no improvements after that as his car was parked in the middle of the track.
Lotus reserve Karun Chandhok endured a disappointing day, the Indian failing to set a time after his car suffered a gearbox problem early on. Chandhok, replacing Jarno Trulli during the session, managed just two installation laps before being asked to return to the pits.
Apart from Hulkenberg's crash, there were just minor incidents during the first 90 minutes, with several drivers going off track without consequence.
Pos Driver Team Time Laps 1. Mark Webber Red Bull-Renault 1m40.403s 22 2. Vitaly Petrov Renault 1m41.227s + 0.824 20 3. Fernando Alonso Ferrari 1m41.239s + 0.836 22 4. Lewis Hamilton McLaren-Mercedes 1m41.510s + 1.107 23 5. Nick Heidfeld Renault 1m41.580s + 1.177 24 6. Felipe Massa Ferrari 1m41.758s + 1.355 23 7. Jenson Button McLaren-Mercedes 1m41.926s + 1.523 14 8. Adrian Sutil Force India-Mercedes 1m41.955s + 1.552 20 9. Nico Rosberg Mercedes 1m42.043s + 1.640 22 10. Jaime Alguersuari Toro Rosso-Ferrari 1m42.216s + 1.813 29 11. Michael Schumacher Mercedes 1m42.270s + 1.867 26 12. Daniel Ricciardo Toro Rosso-Ferrari 1m42.412s + 2.009 27 13. Rubens Barrichello Williams-Cosworth 1m42.704s + 2.301 23 14. Sergio Perez Sauber-Ferrari 1m42.738s + 2.335 20 15. Pastor Maldonado Williams-Cosworth 1m42.841s + 2.438 28 16. Sebastian Vettel Red Bull-Renault 1m42.941s + 2.538 21 17. Kamui Kobayashi Sauber-Ferrari 1m43.201s + 2.798 18 18. Nico Hulkenberg Force India-Mercedes 1m43.769s + 3.366 7 19. Heikki Kovalainen Lotus-Renault 1m44.136s + 3.733 17 20. Jerome D'Ambrosio Virgin-Cosworth 1m45.026s + 4.623 17 21. Timo Glock Virgin-Cosworth 1m45.221s + 4.818 19 22. Tonio Liuzzi HRT-Cosworth 1m45.494s + 5.091 24 23. Narain Karthikeyan HRT-Cosworth 1m46.926s + 6.523 27 24. Karun Chandhok Lotus-Renault 2 All Timing Unofficial