DeltaFin Kawasaki's Kenan Sofuoglu robbed Britain's Sam Lowes of the top time during second free practice at Imola in Italy.
Lowes had been sitting pretty at the head of the timesheets for much of the session on his Bogdanka PTR Honda CBR600RR before the Turkish star pulled the pin to end FP2 with the fastest time.
Sofuoglu appeared to be feeling the effects of a knee strain during the first qualifying session when he could only manage 13th, but he put any doubts about his pace to bed with a strong showing in FP2.
World Supersport veteran Fabien Foret was third fastest on the Intermoto Step Kawasaki with Broc Parkes fourth quickest during the session on the Ten Kate Honda.
South Africa's Sheridan Morais, an impressive sixth on his debut with the DeltaFin Kawasaki team at Phillip Island last month, was fifth.
Morais had led the field in the first qualifying session on Friday but was unable to hit the same heights in FP2 on his ZX-6R.
Local hero Roberto Tamburini was sixth on the Lorini Honda as he continues to raise hopes of a popular result on home soil at Imola on Sunday.
Jules Cluzel, hugely impressive at Phillip Island last month, was 11th on the PTR Honda.
His team-mate Ronan Quarmby was seventh on the PTR Honda CBR600RR, while Vittorio Iannuzzo was next on the Power Team Suriano Triumph 675.
Vladimir Leonov from Russia was the top Yamaha rider in 15th place.
Britain's Martin Jessopp was 17th on the Riders PTR Honda as he continues to re-familiarise himself with the Italian circuit.