The two-time World Champion delivered a 1:31.116 on soft tyres to finish more than a tenth ahead of Ferrari’s Charles Leclerc. Max Verstappen followed in third, as the Red Bull driver tested updates to his RB21 in a bid to close down McLaren’s points advantage in the championship fight.
The session began with immediate drama for Williams, as Alex Albon’s rear brakes caught fire on his out-lap. The flames forced the Thai driver into the pits, ending his running before he could set a time.
That left Carlos Sainz to represent the team alone, with the Spaniard briefly topping the times before dropping to eighth.
Track conditions evolved quickly in the fading light, with several drivers taking turns at the top of the leaderboard. Verstappen and Leclerc both led the way before Alonso seized control with 10 minutes remaining.
Lewis Hamilton took fourth for Ferrari, while McLaren showed solid pace with Oscar Piastri and Lando Norris finishing fifth and sixth.
Racing Bulls’ rookie Isack Hadjar impressed in seventh, ahead of Sainz, Red Bull’s Yuki Tsunoda and Haas’ Esteban Ocon, who rounded out the top ten.
Mercedes kept their focus away from the soft tyre, with George Russell and teenager Kimi Antonelli ending the hour in 11th and 14th.
Lance Stroll endured a difficult session in the second Aston Martin, finishing only 18th.
Full FP1 classification confirmed Alonso at the top, with Leclerc, Verstappen, Hamilton and the McLarens close behind, setting up a competitive weekend.
2025 Singapore Grand Prix – Free Practice 1 F1 results (Marina Bay)
1. Fernando Alonso Aston Martin 1:31.116
2. Charles Leclerc Ferrari +0.150
3. Max Verstappen Red Bull +0.276
4. Lewis Hamilton Ferrari +0.364
5. Oscar Piastri McLaren +0.365
6. Lando Norris McLaren +0.582
7. Isack Hadjar Racing Bulls +0.639
8. Carlos Sainz Williams +0.696
9. Yuki Tsunoda Red Bull +0.744
10. Esteban Ocon Haas +1.012
11. George Russell Mercedes +1.023
12. Nico Hulkenberg Sauber +1.199
13. Pierre Gasly Alpine +1.262
14. Kimi Antonelli Mercedes +1.283
15. Liam Lawson Racing Bulls +1.345
16. Oliver Bearman Haas +1.422
17. Gabriel Bortoleto Sauber +1.495
18. Lance Stroll Aston Martin +1.918
19. Franco Colapinto Alpine +2.208
20. Alex Albon Williams No time
The Singapore Grand Prix continues on Saturday with final practice and qualifying, before Sunday’s 61-lap race around the 5.063-kilometre Marina Bay Street Circuit.
