Thomas Luthi emerged with the fastest time after a frantic conclusion to final practice for the Moto2 Grand Prix of Portugal.
After the morning's 125cc and MotoGP practice sessions were run in damp conditions, the Moto2 field will have been relieved to be running on slick tyres as they made their final preparations for qualifying.
The first half of the 40 minute session became a private duel between Scott Redding and Turkish rider Kenan Sofuoglu as they traded the fastest time of the session.
Eventually the Technomag–CIP rider set the standard with a 1:45.038 before Yuki Takahashi went six tenths quicker than the pair of them.
Luthi took his turn at the top with 13 minutes remaining before Sofuoglu went quicker again, with Pol Espargaro and Redding demoting Luthi to fourth.
That became fifth when Bradley Smith hit the front with three minutes on the clock. But Luthi, running close behind the Briton, responded with two consecutive laps in the low 1:43s, with his second good enough to end the session on top.
That second lap proved crucial as Sofuoglu climbed back up to second, only 0.048s slower than the Swiss rider.
This relegated Marc Marquez and Michele Pirro to third and fourth after they had both improved on their final efforts. Simone Corsi finished fifth while Takahashi slipped back to sixth.
Like his fellow countryman leading the way, Dominique Aegerter found time in the dying seconds. The 20-year-old came out of nowhere to take seventh, completing an encouraging morning for the Technomag-CIP team.
The times tumbled so much in the dying seconds that Bradley Smith dropped all the way back to eighth. Scott Redding had fallen even further but improved on his final lap to finish ninth. Completing the British trio was Kev Coghlan, with the Scotsman struggling down in 37th.
Aside from Luthi, the championship favourites had a quiet session. Stefan Bradl did once get as high as fifth, but the mad scramble at the end relegated him to 21st. Meanwhile, series leader Andrea Iannone never featured near the top of the timesheets and ended up in 26th.