Ferrari were staring at humiliation at the Belgian Grand Prix after Sebastian Vettel finished last in final practice.
While Lewis Hamilton topped the time charts to leave him as favourite for pole position at Spa-Francorchamps, his former championship rival propped up the order.
Vettel's team-mate Charles Leclerc fared little better, finishing 17th in the other Ferrari.
Renault's Esteban Ocon was second, with McLaren driver Lando Norris third. Alexander Albon took fourth for Red Bull ahead of Mercedes' Valtteri Bottas and Max Verstappen.
Ferrari are enduring a poor campaign, but few would have predicted that they would arrive in the Ardennes with the slowest car in the field.
Indeed, Leclerc won here last year with Vettel taking the chequered flag in 2018.
Yet the four-time world champion was beaten by every driver in Saturday morning's one-hour session, 2.1 seconds adrift of Hamilton, with Leclerc 1.9 sec slower.
For Hamilton, it marked the first time he has topped a session this weekend, lapping 0.230 faster than anybody else.
Bottas made a mistake on the entry to La Source, locking up his front-right tyre, and running wide as he exited the opening bend. The Finn finished half-a-second down on his team-mate.
Verstappen, 37 points behind Hamilton in the title standings, was quickest on Friday afternoon, but finished six-tenths back.
British driver Norris will have been encouraged to take third, 0.386 off Hamilton's pace, and six places ahead of Carlos Sainz in the other McLaren.
Qualifying gets under way at 1500 local time.