Dani Pedrosa warned against dismissing the early threat from Valentino Rossi in 2011 after another impressive winter testing display from the Repsol Honda rider in Sepang this week.
The Spaniard set a brilliant best lap of 1.59.803 to finish just 0.138s behind team-mate Casey Stoner on the dominant factory RC212V machine.
He set his best time on only his third lap, utilising the extra grip of Bridgestone's soft compound rear tyre and much cooler conditions as Honda claimed the top four places on the timesheets in Malaysia.
The big shock in Sepang though was the struggle for Ducati, with the fastest GP11 down the rankings in only 10th place with Hector Barbera.
Nine-times world champion Rossi was only 11th fastest and a massive 1.804s behind Stoner as he finished with a time of 2.01.469.
Despite Rossi's battle to find a good set-up with the new Desmosedici, triple world champion Pedrosa was refusing to rule the Italian out of challenging for wins from the first race in Qatar next month.
Pedrosa, who won four races in 2010 before a crash in Japan wrecked his slim title hopes, told MCN: "I expect a big improvement from Valentino in the races. From Saturday to Sunday, even when the bike is maybe the same, he always finds something for the race, so anything is possible with him. The winter tests have been much better than last year but I think we have to expect that everybody will improve and we have to keep our feet on the ground and stick to our plan. Anybody could make a surprise and we have to keep our feet on the ground."