After a morning session led from start-to-finish by MotoGP championship leader Jorge Lorenzo, title rival Dani Pedrosa got the better of the Yamaha rider in FP2 at Motegi, Japan.
Pedrosa and Lorenzo were the only riders to head the timesheets this afternoon - exchanging the top spot several times, before the Repsol Honda rider finished with a slim 0.102s advantage over Lorenzo.
Second to Lorenzo this morning, Pedrosa's best time of 1m 46.088s, set on his penultimate lap, was just under the official race lap record.
Lorenzo, who leads Pedrosa by 33-points with four rounds to go, certainly doesn't look to be riding defensively - giving Hector Barbera a shock by slicing under the Pramac Ducati rider in the closing stages.
Lorenzo's 2013 team-mate Valentino Rossi caused a greater surprise by launching into third with just a few minutes to go, before being bumped to fifth (+0.599s) by even later progress from Andrea Dovizioso (Tech 3 Yamaha) and Stefan Bradl (Honda LCR).
Lorenzo's present team-mate Ben Spies, making his final Japanese GP appearance for Yamaha, slotted into sixth (+0.824s).
After suffering a technical problem within a few turns of his MotoGP comeback this morning, healing double world champion Casey Stoner completed a full session this afternoon - but was regularly in and out of the pits for adjustments to his RCV.
The Repsol Honda star, fourth (+0.758s) in FP1, could only manage seventh (+0.890s) in FP2 and was seen having an animated debrief with his crew after the session.
Friday marked Stoner's first track action appearance since Indianapolis in mid-August, after which the Australian underwent surgery due to ankle fractures and ligament damage sustained in the qualifying session.
A fraction behind Spies and Stoner on Friday was Gresini Honda's Alvaro Bautista, with Cal Crutchlow ninth for Tech 3 Yamaha - but only 0.072s from Spies.
A 0.6s gap then followed to Ducati's Nicky Hayden, who completed the top ten.
Yamaha test rider Katsuyuki Nakasuga has been granted a wild-card entry for the factory in his home round.