Monza, Italy - Lewis Hamilton wasted no time in asserting himself in Italian Grand Prix practice on Friday with the Mercedes driver lapping more than half a second quicker than anyone else at the fastest track on the calendar.
The Briton, who retired in Belgium 12 days ago after team-mate and championship leader Nico Rosberg hit the back of his car, ended the session with a best time of one minute, 26.187 seconds.
Jenson Button, his former team-mate at McLaren, was second fastest on a dry track in 1:26.810, with Rosberg - who has never been on the Monza podium - pushed back to third on the timesheets in 1:26.995.
Hamilton is 29 points behind Rosberg in the championship with seven races remaining and is determined to claw his way back against his German rival, who was punished by the team for the collision.
Ferrari's Fernando Alonso was fourth fastest with Danish rookie Kevin Magnussen reinforcing Button's strong showing with the fifth best time for McLaren, who last won a race in 2012.
RED BULL SIDELINED
Red Bull's quadruple world champion Sebastian Vettel, last year's winner at the 'cathedral' of Italian motorsport, was only sixth fastest while Australian team-mate Daniel Ricciardo was back in 16th.
Ricciardo, as good as Italian to many of the home fans and chasing his third win in a row, was sidelined for some of the session with a power unit problem.
The Williams pairing of Valtteri Bottas and Felipe Massa were 12th and 13th but are likely to look more competitive in the afternoon.
At the slow end of the field, Spanish driver Roberto Merhi made his debut appearance at a Formula One weekend and lapped faster than regular race driver Marcus Ericsson in the other Caterham.
Merhi will hand the car back to Japanese Kamui Kobayashi, returning after being dropped by the team for Spa, for the rest of the weekend.
Spanish reserve driver Daniel Juncadella also had a stint with Force India while Frenchman Charles Pic was handed compatriot Romain Grosjean's Lotus for the session.
ITALIAN GRAND PRIX - FIRST PRACTICE
1. Lewis Hamilton (Britain) Mercedes 1:26.187
2. Jenson Button (Britain) McLaren 1:26.810
3. Nico Rosberg (Germany) Mercedes 1:26.995
4. Fernando Alonso (Spain) Ferrari 1:27.169
5. Kevin Magnussen (Denmark) McLaren 1:27.228
6. Sebastian Vettel (Germany) RedBull - Renault 1:27.271
7. Kimi Raikkonen (Finland) Ferrari 1:27.493
8. Sergio Perez (Mexico) Force India - Mercedes 1:27.687
9. Daniil Kvyat (Russia) Toro Rosso - Renault 1:27.741
10. Nico Huelkenberg (Germany) Force India - Mercedes 1:28.112
11. Esteban Gutierrez (Mexico) Sauber - Ferrari 1:28.114
12. Valtteri Bottas (Finland) Williams-Mercedes 1:28.148
13. Felipe Massa (Brazil) Williams-Mercedes 1:28.150
14. Jean-Eric Vergne (France) Toro Rosso - Renault 1:28.300
15. Giedo van der Garde (Netherlands) Sauber - Ferrari 1:28.429
16. Daniel Ricciardo (Australia) RedBull - Renault 1:28.487
17. Daniel Juncadella (Spain) Force India - Mercedes 1:29.192
18. Pastor Maldonado (Venezuela) Lotus - Renault 1:29.512
19. Max Chilton (Britain) Marussia - Ferrari 1:30.017
20. Jules Bianchi (France) Marussia - Ferrari 1:30.081
21. Charles Pic (France) Lotus - Renault 1:30.125
22. Roberto Merhi (Spain) Caterham - Renault 1:30.704
23. Marcus Ericsson (Sweden) Caterham - Renault 1:30.948