Good morning and welcome to our live text commentary of Free Practice one of the inaugural South Korean Grand Prix! Well done if you've made the effort to stay up so late, you're saints and heroes, the lot of you. It's 09:40 in Korea Standard Time, and we're 20 minutes away from the start of FP1!

So, Hamilton left it late, but that's a decent drive from the Englishman in the end. Kubica also looks like he's up for the challenge this weekend as Ferrari (as ever) keep their cards close to their chests. Don't read too much into these times, as they will get faster, but you'll have to join us at 6am (BST) if you're going to find out how much faster they're going to get! See you in two and a half hours for FP2.

So, it's Hamilton fastest with a 1:40.887, followed by Kubica (+0.081), Rosberg (+0.265), Vettel (+0.484), Button (+1.053), Schumacher (+1.135), and Webber (+1.315)

Hamilton pits, as Rosberg and Vettel dump Button down to fifth-fastest with times of 1:41.152 and 1:41.371 respectively

And there it goes. Kubica and Button battle for second fastest, but the Renault driver comes out on top with a 1:40.968, joining Hamilton as the only driver to go sub 1:41

Hamilton answers back with a 1:40.887, a full second faster than Button! Stunning stuff from the McLaren driver, with the checkered flag moments away

It doesn't last long though! Button snatches the fastest time from under Hamilton's nose, clocking 1:41.940! The McLaren one-two doesn't last long, however, with Robert Kubica posting a 1:41.981

Hamilton goes fastest! The Englishman saves his speed for the final few minutes, and immediately goes fastest with a 1:42.208

So, with five minutes remaining, it's Rosberg fastest (1:42.532), ahead of Hulkenberg (1:42.678), and Barrichello (1:42.883)

Turn one still looks outrageously dusty, despite an hour and 20 minutes of practice! Button looks to be heading for a quick lap, but loses it in the final sector and ends up third-fastest, 0.242 slower than Rosberg

Nico Rosberg usurps his namesake Hulkenberg with the fastest lap-time: a 1:42.532

Jarno Trulli has retired with a gearbox problem, after notching a fastest time of 1:51.701 - right at the bottom of the timings. Shame for the Lotus driver, but he'll be back out at 6am (BST) for FP2!

Hamilton's engine cover has been put back on, and he'll be out soon to finally set that lap-time with 12 minutes remaining!

Not for long though! Hulkenberg goes fastest again with a 1:42.678! Rubens Barrichello comes close to immediately topping his Williams team-mate's time, but crosses the line two-tenths of a second back. It's a Williams one-two at the top at the moment!

The yellow flags are back in, and Button is still fastest with that 1:43.096

Hamilton replaces his rear wing in the McLaren garage, switching to the new rear wing that has served Jenson Button well so far in this practice session. Still no lap-time...

Senna spins off in spectacular fashion at turn seven! Looks like a suspension failure on the left rear wheel. Yellow flags out...

Renault on Twitter: "Vitaly (Petrov) says that the track conditions are getting better now"

25 minutes to go in FP1! Webber is back out, and Hamilton has still yet to post a lap-time! The McLaren team are working on the back of Hamilton's car in the garage, and there's clearly an issue there.

Button posts the new fast time of 1:43.096, before heading into the pits for a debrief. A minor brake issue on Mark Webber's right wheel see the Aussie go back into the garage.

McLaren to Hamilton: "Lewis, these next timed laps will hopefully give you a feel for the circuit."