FP1: Perez, Sainz and Verstappen lead the opening practice session in Monaco

Fans were back in the grandstands lining the sun-soaked Monte Carlo streets to witness Sergio Perez set the fastest lap in first practice for Sunday's Monaco Grand Prix, ahead of Ferrari's Carlos Sainz and Max Verstappen – the top three split by just 0.161s.

Red Bull, hunting for their first victory in Monaco since 2018 – and first win since Imola – had soft tyre-shod Perez set the benchmark late in the session, improving to 1m12.487s with his final run. Medium-tyred Sainz was second by just 0.119s in an impressive showing for Ferrari, followed by Verstappen on the same compound, another four-hundredths of a second off.

READ MORE: Will the tight confines of Monaco be the place Hamilton and Verstappen's rivalry bubbles over?

Pierre Gasly put his soft-tyred AlphaTauri fourth, four-tenths off the pace. That left the medium-tyred Mercedes of Lewis Hamilton and Valtteri Bottas in fifth and sixth respectively.

Charles Leclerc, sporting a helmet in tribute to Monaco legend Louis Chiron, began the session waving to his home fans, but the Ferrari driver's gearbox gave way soon after and his session was over after just four laps. He finished bottom of the time sheets as a result.

Lando Norris - fresh from penning a new McLaren contract - finished seventh fastest and team mate Daniel Ricciardo 15th in the one-off Gulf-liveried MCL35Ms that looked resplendent around the streets of Monaco.

READ MORE: How McLaren are trying to stay ahead of Ferrari – and the front wing call they have to make for Monaco

Aston Martin's Sebastian Vettel won here in 2011 and '17, but is still getting to grips with things at his new team. He finished eighth, behind Norris, while team mate Lance Stroll was 11th. Between them was AlphaTauri's Yuki Tsunoda (P9) - who is competing at Monaco for the first time in his racing career - and 10th-place Kimi Raikkonen for Alfa Romeo.

Antonio Giovinazzi was next, in 12th, and behind the Alfa Romeo in the standings was 13th-place Fernando Alonso of Alpine. Winner here in 2006 and '07, Alonso tapped the wall on Thursday morning in the final corner and brought out a Virtual Safety Car just before the half-way point of the session. Team mate Esteban Ocon, ecstatic about returning to Monaco after a three-year absence, took 16th overall.

Williams celebrate their 750th Grand Prix this weekend and their drivers sported special helmets while the cars had a tweaked livery, featuring the names of 100 fans on their halos, for the occasion. Nicholas Latifi took 14th while George Russell finished 19th.

The Haas pair, Nikita Mazepin and Mick Schumacher, put their cars 17th and 18th respectively, in their first F1 outings at the Principality.