Nicky Hayden enjoyed a dramatic performance surge at Sepang on Friday - shredding 1.5 seconds from his best lap time to claim third on the end-of-test timesheets, in what Valentino Rossi called "the greatest surprise of the day".

Hayden, weakened by recent surgery to remove scar tissue from a previous arm-pump operation, had been only eleventh out of the 16 riders during day one - but the suffocating heat had masked the amount of progress made.

"Yesterday I had a lot of chatter and I just couldn't get through the long corners," said Hayden, speaking exclusively to Crash.net.

"But we made some changes at the end of yesterday, which made me a few tenths faster even in the heat. Then we tweaked it a bit more this morning and the bike worked really well in the cooler temperatures we've had today.

"I had a lot better feeling and was able to go a lot faster. I'm pretty happy.

"My best time was set with the standard tyre. I tried the new Bridgestone rear, but I was faster with the standard one.

"We're pretty much set on the swingarm and geometry to use at the start of the season now, although obviously we'll want to confirm a few things at the Qatar test, under different conditions," he added.

Team-mate Casey Stoner has won 20 races for Ducati since the start of 2007, compared with just one win (by Loris Capirossi) for all other Ducati riders combined.

But Sepang featured the rare sight of two factory Ducatis in close formation at the sharp end of the timesheets, with Hayden's best lap just 0.191sec slower than Stoner and within 0.44sec of Rossi (around a long lap of over two minutes).

Hayden believes a few more tenths will be instantly available if he and Ducati can find a solution for the top speed deficit he has struggled with ever since getting on the Desmosedici.

"I'm still down on top speed. Actually on my best lap I was two tenths quicker than Casey up until the back straight," Hayden revealed. "Coming on the back straight and to the finish line I lost it. You can do the maths [regarding how much speed he is down]. I don't want to get carried away though. That was only on my best lap, not every lap."

Nevertheless, Friday's form was just what Hayden needed with only one test session remaining before the start of a crucial second season at Ducati.

"I left here last night thinking 'over the last two days of testing I've only gone half a second quicker'. Sore arm or not that just ain't good enough," declared Hayden, holding a bag of ice on his arm. "I was feeling pretty frustrated. But now we've gone a lot quicker."

And the faster you go, the better it feels.

"The closer you get to the limit and the faster you go, especially on the Ducati, the better a MotoGP bike feels," said Nicky.

"When you are two seconds off the pace it feels miserable. But when you're 'on it' and the bike's working, those are the moments you live for," smiled the 2006 world champion.

Hayden's first season at Ducati was highlighted by a podium at his home Indianapolis round.

The third and final 2010 MotoGP pre-season test will be held at Qatar on March 18-19.