Hamilton quickest in China practice
Lewis Hamilton left it until the last possible moment to post the quickest lap in first practice for Sunday's Chinese Grand Prix.
It was not until the closing stages that Hamilton took advantage of a dry line around the Shanghai International Circuit.
In posting a time of one minute 37.106seconds, Hamilton finished 1.010secs quicker than Mercedes' Nico Rosberg.
Overnight rain forced a slow start before the majority of the drivers finally made their way out on to the circuit, initially on the intermediate Pirelli tyres to cope with the conditions. By not venturing out until late on, however, both Hamilton and McLaren team-mate Button have saved a set of inters ahead of the weekend.
Rosberg's team-mate, seven-time champion Michael Schumacher, was 0.2secs down on his fellow German, with the duo followed by the Saubers of Sergio Perez and Kamui Kobayashi.
Mark Webber finished 1.871secs adrift of Hamilton, who this weekend faces a five-place grid penalty for a gearbox change. The issue was discovered earlier this week, with the team opting to run the old gearbox in practice ahead of changing it for qualifying.
The remainder of the field, spearheaded by reigning world champion Sebastian Vettel in seventh, were all at least two seconds down.
That included Button who was only a thousandth of a second behind Vettel, but 2.093secs off of Hamilton, with the Toro Rosso pair of Daniel Ricciardo and Jean-Eric Vergne completing the top 10, but with both 2.6secs off the pace.
They were followed by the Ferraris of championship leader Fernando Alonso and Felipe Massa nearly three seconds back.
Three reserve drivers in Williams' Valtteri Bottas, Giedo van der Garde at Caterham and Force India's Jules Bianci were all given a run out, finishing 13th, 19th and 20th respectively. Lotus' Kimi Raikkonen, who struggled with a rear-wing issue, was left at the back of the field, the Finn 13.3secs down.