Casey Stoner remained on top of the timesheets during Saturday morning's sunny final practice session at Catalunya, but home hero Jorge Lorenzo was just 0.122sec behind.
Repsol Honda rider Stoner, the only double winner so far in 2011, had enjoyed a 0.528sec advantage over Marco Simoncelli by the end of Friday's rain-interrupted sessions, with the top Yamaha of Lorenzo trailing Stoner by 0.870sec in fourth.
San Carlo Honda Gresini rider Simoncelli also gained ground on Stoner, reducing the deficit to 0.439sec as the Italian took third place on Saturday morning.
Lorenzo's team-mate Ben Spies continued his promising Friday form with fourth place (0.787s), having pushed Stoner's team-mate Andrea Dovizioso down to fifth (+0.937s).
The top Ducati was Nicky Hayden in sixth (+0.978s), with rookie Cal Crutchlow - the lone Monster Yamaha Tech 3 rider after Friday's collarbone injury for Colin Edwards - 1.2sec from Stoner in seventh place.
Valentino Rossi was suddenly dumped from his Ducati after losing the front with eleven minutes to go, triggering the airbag in his leathers. The Italian was unhurt and remained in eighth place (1.673s), where he had been at the time of his spill.
Fellow Italian Loris Capirossi also fell from his Desmosedici, while 15th and last, but had improved to ninth by the end of the 45 minutes.
Qualifying takes place this afternoon.
Friday practice (3):
12. de Puniet