An early shower Saturday morning meant the track surface in Singapore was fairly green at the start of the session – which ran in the dry.
Ferrari locked out the top positions in Friday practice, with Charles Leclerc quickest in FP1 before Sainz went quickest in the more representative FP2 session under the cover of night.
The Scuderia looked to continue their fine form into Saturday and the pair were entrenched in the top-5 at the start of the session courtesy of laps on the medium compound.
Red Bull struggled yesterday – particularly in FP2 where they finished seventh and eighth respectively, with Sergio Perez ahead of Max Verstappen – so the pair looked to turn things around in FP3.
At the start of the session, Perez complained that his RB19 felt “too pointy” and Verstappen was seen taking to the run-off on a cooldown lap, so all wasn’t plain sailing for the champions-elect.
But the Dutchman was in a feistier mood compared to yesterday and set a benchmark time of 1:33.660s 15 minutes into the session on the medium compound.
Mercedes by all accounts had a strong Friday, with Lewis Hamilton hailing FP2 the “best” of 2023.
The Brackley-based team managed to carry impressive pace in FP3 as well, with Russell sitting at the top of the leaderboard at the halfway point thanks to a lap on soft tyres of 1:32.883s with Hamilton two-tenths behind in second.
As daylight began to fall and temperatures cooled, more runners switched to the soft tyre and the pace ramped up, with Russell pushing the benchmark by a further five-tenths on a fresh set of softs with 18 minutes left to run.
He was then usurped by Lando Norris, who continued his fine form in the heavily updated McLaren, with a time of 1:32.303s.
But with 10 minutes to go Sainz punched in a 1:32.065s to stake his claim at the top, showing impressive pace on the softs that would see him remain fastest through to the end of the session.
Russell’s final push lap saw him finish second by the narrowest of margins, with Norris finishing a fine third in his McLaren.
Verstappen, who spent the majority of the session complaining about upshifts could only muster the fourth best time, with Leclerc bailing on his final push lap to round out the top-five positions.
Hamilton finished sixth in the second Mercedes, with a time 0.470s back from Sainz’s benchmark and Oscar Piastri, without Norris’ updates, managed to finish seventh in the second McLaren.
Perez combated a car he struggled for feeling with throughout to finish eighth and Nico Hulkenberg squeezed his Haas into the top-10 positions with the ninth fastest time.
Completing the top-10 was Yuki Tsunoda, punching in a time 0.880s slower than Sainz in his AlphaTauri.
Next up is qualifying, which commences at 21:00 local time (14:00 BST).