Casey Stoner dodged a gopher to emerge fastest during day one of the 2011 Indianapolis MotoGP, which saw lap times tumble after a controversial debut for the new track surface.

Stoner was one of many to criticise the slippery new asphalt (covering turns 5 to 16) after FP1 - when lap times were around 3-6 seconds off record pace - claiming it was worse than the bumpy patchwork of old tarmac it had replaced.

Circuit conditions seemed to improve significantly in the afternoon and Stoner's final lap, which put him 0.194sec ahead of home star and morning pace setter Ben Spies (Yamaha), was within 0.58sec of the official lap record.

However the Australian insisted conditions were still far from normal.

"This afternoon the track was slightly better and of course the lap times improved with more bikes on track and cleaning it up, but I'm still not comfortable on this surface," he said.

"It's incredibly slippery and the track is certainly my least favourite of the whole season.

"It's very tight, slippery and the new surface is pretty bad, it's not just the dirt on the surface but there seems to be something strange where the two surfaces join, some grease of some sort that creates more issues.

"With this said, we couldn't find too much with the bike, we made a small step this morning and a small step this afternoon but we're struggling to get a good feeling in the bike.

"We tried the harder front this afternoon which gave us good feedback and we were able to go a little bit faster, but in general the track needs to improve before we can know what direction to go in and I just hope the conditions improve for the race."

As if the slippery circuit wasn't enough to contend with Stoner, who holds a 32-point title lead over Spies' team-mate Jorge Lorenzo, had to take avoiding action when a creature ran across in front of his Repsol Honda.

"My last few exits were slightly ruined from traffic on track and also wildlife! I saw something out the corner of my eye, I'm not sure what it was - perhaps a gopher or something. I thought it was a part from someone's bike, I'm just glad we both escaped from that situation unharmed!"

Stoner's team-mate and defending Indy winner Dani Pedrosa, who branded the asphalt "not what a World Championship circuit deserves" in the morning, was slightly happier after improving from tenth to third.

"The track improved a little in the second practice session, at least on the racing line, but outside the line the surface is still very dirty and slippery. However, we made some better lap times; it's just about getting a good set-up with the tyres and trying to take care of them," he said.

"Let's hope that the conditions keep improving throughout the weekend and we can keep working step by step on the set up considering that the tyres will be the key point in this race. In general, I'm happier than this morning, we were able to improve by four seconds in just one session, but we have to keep focused and make another step forward tomorrow".

Andrea Dovizioso, who made it three Repsol riders in the top five, is now firmly focussed on tyre conservation.

"With more rubber on track, the grip changed quickly and now the main issue is tyre wear," he said. "This is typical for new asphalt so we have to manage the tyres carefully, with special attention on the front tyre. The key point for the race will be managing the tyres.

"I hope that conditions will improve again tomorrow as with today's situation it's impossible to finish the race," he warned.