Hamilton edges Rosberg in Monza FP2

Although the gap from the fastest Mercedes time to best-of-the-rest Sebastian Vettel's Ferrari in third came down from the morning's 1.5-second gulf to a less daunting seven tenths, the champion team and its newly upgraded engine remained a class apart.

Hamilton was three tenths of a second faster than Rosberg by the time they had finished their opening runs on medium tyres.

It looked like the German might upstage his title rival on softs as he set a quicker pace through the lap's first two sectors when they changed emphasis in the middle of the session.

But Rosberg lost time on the run through the Parabolica and fell short by 0.021s at the line.

Ferrari had initially held a crowd-pleasing one-two in the early moments before the Mercedes got up to speed.

Vettel and Kimi Raikkonen ended up third and sixth, split by the Mercedes-powered Force Indias of Sergio Perez and Nico Hulkenberg.

The Ferraris were the only non-Mercedes-powered cars in the top 10, as Lotus pair Romain Grosjean and Pastor Maldonado led Valtteri Bottas and Felipe Massa in seventh through 10th places.

While plenty of drivers visited chicane escape roads or flirted with track limits misbehaviour, the most attention-grabbing incident came from a Toro Rosso rookie again.

After Carlos Sainz Jr's high-speed spin into the Parabolica in the morning, it was Max Verstappen's turn in practice two.

He lost it under braking into the Ascari chicane and flew backwards into the gravel, stopping just before the tyre wall and managing to plough his way out.

Drivers in mechanical trouble included Daniel Ricciardo, who had to crawl back to the Red Bull pits in first gear due to a hydraulic problem. It was rectified in time for him to rejoin later.

His team-mate Daniil Kvyat spent most of the session on medium tyres and was slowest as Red Bull - guaranteed tail-end starts as it makes a double engine change on both cars - opted out of trying for low-fuel times.

Kvyat was slower even than Jenson Button, who managed only three laps before McLaren summoned him into the pits with a technical worry.