With speculation about the German’s future in Formula 1 continuing, the Mercedes driver responded in ideal fashion with a time of 1:25.422.
Last weekend’s Belgian Grand Prix winner Jenson Button was second for McLaren – 0.301 seconds behind – with German driver Nico Rosberg of Williams third.
An enthusiastic crowd watched as drivers battled to tame the fastest track on the Formula 1 calendar, with many struggling to slow down for the chicanes at turns one and three.
Most notably, Kimi Raikkonen’s Lotus took to the air after hitting a curb at the Variante della Roggia chicane.
As has been traditional for first practice sessions this season, the opening 30 minutes saw limited activity with just four drivers setting competitive lap times.
However, with an hour of the session remaining, the session burst into life, with the majority of cars taking to the Monza tarmac.
With many championship contenders trading fastest lap times, it was Schumacher who produced the quickest run with 48 minutes remaining.
The session ended in disappointment for championship leader Fernando Alonso as he stopped on the exit of turn one with a reported engine problem in the closing minutes of the session.
HRT’s development driver Ma Qing Hua made history by becoming the first Chinese driver to participate in part of a Formula 1 race weekend.
1 Michael Schumacher (Ger) Mercedes GP 1:25.422
2 Jenson Button (Gbr) McLaren (+0.301)
3 Nico Rosberg (Ger) Mercedes GP (+0.340)
4 Fernando Alonso (Spa) Ferrari (+0.378)
5 Felipe Massa (Bra) Ferrari (+0.439)
6 Lewis Hamilton (Gbr) McLaren (+0.522)
7 Kimi Raikkonen (Fin) Lotus F1 Team (+0.624)
8 Sergio Perez (Mex) Sauber-Ferrari (+0.901)
9 Mark Webber (Aus) Red Bull (+0.968)
10 Pastor Maldonado (Ven) Williams (+1.082)
11 Sebastian Vettel (Ger) Red Bull (+1.086)
12 Nico Hulkenberg (Ger) Force India (+1.096)
13 Valtteri Bottas (Fin) Williams (+1.219)
14 Kamui Kobayashi (Jpn) Sauber-Ferrari (+1.324)
15 Jerome d’Ambrosio (Bel) Lotus F1 Team (+1.758)
16 Jules Bianchi (Fra) Force India (+1.770)
17 Daniel Ricciardo (Aus) Scuderia Toro Rosso (+1.951)
18 Jean-Eric Vergne (Fra) Scuderia Toro Rosso (+2.367)
19 Heikki Kovalainen (Fin) Caterham (+2.433)
20 Vitaly Petrov (Rus) Caterham (+3.156)
21 Charles Pic (Fra) Marussia (+3.329)
22 Timo Glock (Ger) Marussia (+3.785)
23 Pedro de la Rosa (Spa) HRT-F1 (+3.909)
24 Ma Qing Hua (Chi) HRT-F1 (+5.817)
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BIOGRAPHY: Ethan Hazard
BIOGRAPHY: Daniel Sturridge