Lewis Hamilton headed Max Verstappen by 0.143 seconds to lead the way in second practice at the Portuguese Grand Prix.
The second Mercedes of Valtteri Bottas was third quickest, ahead of Ferrari’s Carlos Sainz and the Alpines of Fernando Alonso and Esteban Ocon.
It is the first time this season that Hamilton has topped a practice session.
“It is going to be a close-run thing. I don’t know how Max’s lap was, but mine wasn’t perfect. It’s close, so it’s exciting,” he said.
“It’s very windy today. I think everyone was struggling sliding around out there. Everyone looks like they’re struggling with their balance. It has definitely been a real challenge to keep the car on track.”
Bottas was 0.334secs behind Hamilton, as less than 0.1secs separated the Finn from the three drivers immediately behind him.
Ferrari’s Charles Leclerc was seventh fastest, ahead of McLaren’s Daniel Ricciardo. Aston Martin’s Lance Stroll and Perez completed the top 10.
All the drivers were struggling in the windy conditions close to the coast and on a track that was newly resurfaced before last October’s inaugural grand prix at Portimao.
Verstappen said: “It’s super-slippery. I know it is the same for everyone but it is not very enjoyable to drive. The car felt all right. Some work to do for tomorrow but overall it’s fine.
“It’s very tricky out there and it’s a shame because it’s all about tyre prep and tyre temperature and it shouldn’t be like that.”
Mercedes and Red Bull appeared closely matched on both one-lap pace and on a longer race-simulation run.
What about those Alpines?
Practice is not always an accurate reflection of true pace, but on the face of it Alpine produced their most competitive showing of the year so far on the undulating Portimao track on the Algarve.
The Anglo-French team, formerly known as Renault and who scored three podium finishes in the second part of last season, have been towards the back of the midfield in the first two races this season, but have brought some new aerodynamic parts to this race.
A new floor has been added to the front wing update that was introduced at the last race at Imola.
Alonso, returning to F1 this year after two years away, had a difficult time at Imola, admitting after qualifying that he was “not fast” and vowing to improve in Portugal.
And on first evidence he appears to have done so, leading the way for Alpine, albeit just 0.015secs quicker than Ocon, who improved on his second flying lap to move closer to the two-time champion after being 0.2secs off on his first run.
The 39-year-old, who had never driven at Portimao before, said he had “enjoyed” the track, adding: “It was a good practice day for me and the most comfortable I’ve had this season compared to Bahrain and Imola.
“I was happy with the set-up of the car quite early in the day, so I concentrated mostly on becoming more acclimatised to the circuit and then evaluating the tyres over the two sessions.”
Lando Norris, who is third in the championship behind Hamilton and Verstappen after finishing fourth and third for McLaren in the first two races of the season, said: “The Alpine was very fast. We had a big gap to the Alpine the last two weekends but this week they seem a lot more competitive.
“It’s two more cars we might be racing. It’s exciting but it makes our life a bit more tricky.”
Norris, who was 12th fastest on Friday, said: “The car balance maybe isn’t quite as good as the last two weekends. So we still have a lot of work to do and we are not confident of being in the top 10. It is a bit tougher than we expected.”
However, Alonso said: “I think the positions will not be too different compared to Imola or Bahrain. I don’t think there is any big changes in the order. It is just a diffident Friday and a different approach from teams, but fingers crossed we can keep this pace tomorrow.”
The long runs suggested Ferrari and McLaren were closely matched on pace behind Mercedes and Red Bull, with the Alpine a little slower.
Sebastian Vettel continues to find his feet in the second Aston Martin and was down in 15th place.
The race-simulation runs at the end of the session suggested that the favoured race-start tyre may be the medium – as it has been at both races so far this year.
So the leading teams will probably try to use that tyre to set their times in second qualifying on Saturday to ensure it can be their compound for the start of the race.