Valtteri Bottas edged out Lewis Hamilton in final practice for the French Grand Prix.
After dominating the running on Friday, Mercedes were again the team to beat, with Bottas finishing just 0.041 seconds clear of Hamilton.
Ferrari's Charles Leclerc and Sebastian Vettel were third and fourth in the order, nearly half-a-second adrift of Bottas' Mercedes.
Mercedes have been the class of the field this season, winning all of the opening seven races, and it seems inevitable that they will lock out the front row in qualifying later.
Hamilton and Bottas have been evenly matched in the running so far, with the Finn 2-1 up in the three sessions.
Ferrari, boosted by a number of new parts on their cars this weekend, would have hoped to carry over their form from Canada - a race Vettel was due to win before he was penalised five seconds for falling off the track and rejoining it in a dangerous manner.
Yet, neither the German nor Leclerc have been anywhere near the Mercedes cars at the Circuit Paul Ricard in the sun-bathed south of France.
Red Bull driver Max Verstappen finished fifth, 1.4 sec slower than Bottas with his team-mate Pierre Gasly sixth in the order.
British teenager Lando Norris has gone well this weekend, and he was an encouraging seventh for McLaren, just 0.055 sec behind Gasly's Red Bull.
A power issue on George Russell's Williams meant the British novice failed to post a competitive time.