The Ferrari driver was two-tenths clear of second-best Max Verstappen in the final practice hour, the Red Bull Racing driver continuing to wrestle his car around the lap, his true pace was masked by traffic.
Mercedes too appears in the fight, with Lewis Hamilton continuing the good pace he had on Friday, with Oscar Piastri fourth best in the leading McLaren.
Practice on Friday suggested as many as five teams were in the fight for pole position come qualifying later.
Ferrari appeared strong, as did Mercedes, while Aston Martin was a surprise package.
The final practice hour was therefore an opportunity for teams to validate that early pace and, in the case of others, demonstrate potential they believe was there.
Daniel Ricciardo, for instance, ended Friday confident that his car is capable of qualifying inside the top 10. However, he didn’t complete a soft tyre run on the opening day which left him, comparatively, out of position against those who did.
The same was true for Oscar Piastri, who was only 13th in Free Practice 2 but with a McLaren expected to be a strong contender for the front row – and potentially more on Sunday.
Early reports in Free Practice 3 were that the track was around half a second slower than Free Practice 2, as bright skies based the circuit in sunshine versus the overcast conditions on Friday evening.
A mistake from Valtteri Bottas saw the Sauber driver get the wall exiting the Swimming Pool section, breaking his steering and forcing him to stop on the exit of La Rascasse. Blocking more than half the road, it drew the red flag for a total of four minutes.
To that point, 12 minutes into the session, nobody had set a representative lap; Hamilton was fastest on a 1:14.104s – three seconds off Charles Leclerc’s pace from Free Practice 2.
Hamilton torched a set of soft tyres with a monumental lock-up into Sainte Devote, which skidded him into the escape road. Kevin Magnussen had a similar moment, his into Mirabeau.
Times were coming down, and after 25 minutes, Piastri topped the timesheets with a 1:12.875s – on a soft tyre. It was soon beaten by Leclerc, though the Ferrari was not rapid through the middle third of the lap. Even still, the 1:12.521s left him 0.163s faster than Piastri.
Appearing to reinforce Ricciardo’s belief that the RB is a top 10 car this weekend, Yuki Tsunoda went second fastest at the halfway mark of the session, though his 1:12.526s was still slower than what he’d set to end Free Practice 2 in 11th.
Alex Albon was also up the order for Williams, the attention having clearly turned to the day’s later session and rehearsals for that critical hour.
The single-lap runs left Leclerc fastest from team-mate Carlos Sainz. The Ferrari duo was clear of Verstappen in third. Tsunoda’s lap hung on in fifth, behind Hamilton, with Albon eighth.
Only then came the two McLarens, headed by Piastri, who was 0.707s away from the outfight pace and just under a tenth better than Norris.
Aston Martin left its qualifying simulations late, but when Fernando Alonso did complete his first lap, he split the two Ferraris.
With 15 minutes remaining, a second flurry saw Sainz return to second fastest, 0.002s away from Leclerc, while Piastri improved from ninth to sixth and 0.4s away from the pace. The Monegasque driver wasn’t done either and banged in a 1:11.369s to move himself 0.610s clear of the pack.
Traffic prevented Verstappen from showing his complete hand in what was proving an enthralling session full of punch and counter punch as teams auditioned for qualifying later in the day.
A late lap from Verstappen saw the Dutchman rise to second fastest, though was still 0.589s away from Leclerc’s monster earlier effort. He was still far from comfortable, suggesting he’d end up in the fence if he continued to push on.
He did find more time, though, going fastest of anyone in the first split before encountering a veritable traffic jam in the final third of the lap. It masked whatever pace he might have had, and insight into whether he has the pace to challenge Leclerc later today, ending the session 0.197s back from the Ferrari driver.
Third best was Hamilton, then Piastri and Sergio Perez, who improved as the chequered flag waved. Tsunoda was ninth best in the RB, while Ricciardo was 18th, 1.4s away from Leclerc and 0.8s back from his RB team-mate.
Qualifying follows, beginning at 16:00 local time (midnight AEST).