By Alan Baldwin
MEXICO CITY, Oct 30 (Reuters) - Kimi Antonelli reported fit after a bout of sickness and lapped second fastest behind Ferrari's Charles Leclerc in Friday's first practice for a Mexico City Grand Prix set to crown the 20-year-old Mercedes driver as Formula One's youngest champion.
The Italian missed Thursday's media day to recover from a viral illness but started as normal in an opening session without 10 race regulars as all but Ferrari gave track time to young drivers at the Autodromo
Hermanos Rodriguez.
Leclerc set the pace with a lap of one minute 18.128 seconds while Antonelli, 123 points clear of teammate and closest rival George Russell in the standings and needing only two points on Sunday to put the title out of reach, was 0.659 slower.
Russell was one of those sitting out the session with Mercedes reserve Fred Vesti taking his place and lapping third fastest, 0.733 slower than Leclerc, with Ferrari's Lewis Hamilton fourth.
Japanese Ayumu Iwasa, taking the place of four-time champion Max Verstappen at Red Bull, was the fastest of the non-race drivers with fifth on the timesheets.
He was followed by Alpine's Pierre Gasly, Aston Martin's Fernando Alonso, McLaren's Oscar Piastri, Haas's Ollie Bearman and Racing Bulls' Arvid Lindblad.
Bulgarian F2 title contender Nikola Tsolov, taking the place of Liam Lawson at Racing Bulls and still in with a shout of landing the seat for next season, complained of losing sensation in his leg but was a commendable 12th fastest and behind Red Bull's Isack Hadjar.
"Running out of blood on my right leg. I cannot feel my right leg. I think the seat is compressing my leg and my blood stopped," Tsolov said over team radio after returning to the pits.
Team principal Alan Permane called it a "textbook first session" with the F2 driver keeping the car intact and providing good feedback.
British 18-year-old Freddie Slater had a troubled F1 practice debut, with Audi mechanics leaving a cooling fan attached to the side of the car as he went out on track, but he still ended the session off the bottom of the timing screens and with 14 laps completed.
Aston Martin reserve Jak Crawford stopped on track with a suspected power unit issue, triggering a virtual safety car.
Reigning F2 champion Leonardo Fornaroli took world champion Lando Norris's seat for the session and was 17th fastest, with a small tyre lock-up sending the car skidding over the grass.
American Colton Herta was slowest, in Valtteri Bottas's Cadillac, but completed 30 laps to gain another point towards his super licence.
(Reporting by Alan Baldwin, editing by Pritha Sarkar)
