World champion and series leader Max Verstappen sizzled in the sun on Saturday when he topped the times for Red Bull ahead of both Ferrari drivers in third and final practice session at the French Grand Prix.
Making the most of a superior straight-line speed, the 24-year-old Dutchman clocked a best lap in one minute and 32.272 seconds to outpace Carlos Sainz in the leading Ferrari by three-tenths of a second.
Sainz, who claimed his maiden Formula One triumph at the British Grand Prix earlier in July, will start Sunday's race from the back of the grid alongside Jan Magnussen of Haas after the two Ferrari-powered cars took more new engine parts.
Charles Leclerc, who trimmed Verstappen's advantage in the title race to 38 points by winning the Austrian Grand Prix, was third fastest six-tenths down on the pace.
Seven-time champion Lewis Hamilton was fourth for Mercedes ahead of Sergio Perez in the second Red Bull and George Russell, in the second Mercedes.
It was a measure of Verstappen's dominant pace that he was more than a second quicker than his Red Bull teammate on another hot day in the south of France.
Two-time champion Fernando Alonso was seventh for Alpine with a late lap to lift him ahead of Alex Albon of Williams, Lando Norris of McLaren and Yuki Tsunoda of Alpha Tauri.
Both German drivers Mick Schumacher and four-time champion Sebastian Vettel endured difficult sessions and wound up 19th and 20th respectively for the Haas and Aston Martin teams after completing only 12 and 11 laps.
SCORCHING CONDITIONS
In scorching conditions, the session began with only seven cars venturing out and Perez setting the first lap time in 1:33.628 after seven minutes – a time obliterated immediately by Verstappen in 1:32.837 – but little else for the sell-out holiday crowd to enjoy.
As the air temperature rose to 34 degrees, the fans raised a cheer for Pierre Gasly as he passed the grandstand named after him before the Mercedes set times more than 1.5 seconds adrift of the champion. "1.7?" said Hamilton. "Jeeze…"
Ferrari were also struggling to match the Red Bull pace and Leclerc, pushing hard, spun through a full 360 degrees on his hard tyres before Hamilton and Yuki Tsunoda of Alfa Romeo each survived brief 'moments' in pursuit.
Vertappen's pace on medium tyres remained the standard to catch as his rivals tested 'softs' and 'hards' before galvanising themselves for a late flurry of qualifying simulation runs.
With 12 minutes remaining, both Leclerc and Sainz had improved to second and third, but were still 0.1 seconds adrift, with Hamilton fourth, four-tenths down. At this time, Red Bull were still to use soft tyres.
The stubborn Sainz persisted and went top after 51 minutes of the hour, replacing Verstappen in 1:32.626, an advantage of 0.182 to enthuse the 'prancing horse' fans sweltering in the open grandstands.
Finally taking softs, Verstappen re-joined the fray to beat the Spaniard by 0.354 seconds while Leclerc conceded his tyres were 'dead', a familiar Ferrari problem at the high-degradation Paul Ricard circuit.
By this time, the track temperature was 57 degrees – hot enough to pose a serious challenge to cars, drivers and teams and certain to make strategy a major factor in Sunday's race.