Rizla Suzuki’s John Hopkins set the pace in practice ahead of Sunday’s MotoGP in Shanghai.
Second fastest in opening practice, the American went one better in the afternoon session to set a time of two minutes 01.204 seconds to pip Gresini Honda’s Marco Melandri, of Italy, into second.
The top eight were covered by under three tenths of a second, with last year’s race winner Dani Pedrosa third and his Repsol Honda team-mate, world champion Nicky Hayden, fourth.
Ducati have shown exceptional top speed so far this season and Shanghai’s 1.2km straight, the longest on the MotoGP calendar, is expected to play into their hands this weekend.
However, in spite of championship leader Casey Stoner setting the pace in first practice, the top Ducati rider in the afternoon was Italy’s Loris Capirosi, down in fifth.
Hopkins was encouraged by what he had seen, but knows he must capitalise on the twisty parts of the track to counter the formidable outright pace of the Ducatis.
“I know I can overtake into the tight right at turn three so that’s a place where I can get through,” said Hopkins.
“But the worry is if a Ducati gets a little lead then it can make a break with its top-speed advantage on the straight. That’ll be difficult.
“We have made some improvements over the day and we still have a couple of little bits to sort out tomorrow. Competition is really close again and we need to find every tenth of a second we can.”
So tight is it at the front that Capirossi was just 0.161secs from Hopkins and sixth-placed Valentino Rossi only 0.186secs from the front.
Then came the Italian’s team-mate Colin Edwards, with Australia’s Stoner in eighth.
Rossi, whose tyre trouble dropped him from second to 10th last time out in Turkey, is another whose bike cannot match the Ducati for straight-line speed.
But with wet conditions forecast over the weekend, the Fiat Yamaha-riding Italian is hopeful of coming away from China with a win to close in on Stoner in the title race.
He said: “We are missing a little bit of top speed on the straight, but we’re obviously making it up in other areas of the track where our bike is strong.
“Of course it’s always better to race in the dry, but we have had success before under the rain and I think our bike is fast in the wet this year so let’s wait and see.”
Ducati Marlboro’s Stoner, who broke his MotoGP duck with two wins in the first three races of the season, added: “The Ducati is fast here, but the track is also tight and twisty, so we just need to keep our heads together for the race and make the most of it.
“I’m feeling good about this race now that I know what is involved in winning races.”
Meanwhile, Kawasaki’s French rider Olivier Jacque has withdrawn from the event after injuring his arm during practice.