Max Verstappen completed an opening day double in Friday's closely-fought second free practice for this weekend's season-opening Bahrain Grand Prix.
The Red Bull driver outpaced nearest rival Lando Norris of McLaren by 0.095 seconds and third-placed defending seven-time world champion Lewis Hamilton of Mercedes by slightly more than two-thirds.
Ferrari new boy Carlos Sainz, in his first day's work since joining from McLaren, was fourth ahead of Valtteri Bottas in the second Mercedes and Daniel Ricciardo, on his first outing for McLaren.
Japanese rookie Yuki Tsunoda was an impressive seventh for AlphaTauri ahead of Lance Stroll, of Aston Martin, Pierre Gasly in the second AlphaTauri and new recruit Sergio Perez in the second Red Bull.
The one-hour session, reduced from 90 minutes to reduce costs, provided few clear signals for the season ahead other than confirmation that Red Bull are narrowly fastest ahead of a tight pack – separated by very little time.
After a competitive opening session that saw an improved Mercedes ease off as Verstappen went top, the second run began with Hamilton out immediately on mediums in cooler conditions under the lights.
He was soon on top ahead of Bottas before Kimi Raikkonen, at 41 the oldest man in the field, spun his Alfa Romeo at Turn Three, bouncing through the gravel and hitting the wall.
The Finn's accident ripped off the nose and smacked his right rear wheel into the barrier.
A strong swirling wind, which had changed direction in the cooler temperatures, may have helped cause his mishap.
Hamilton then switched to softs with a group of others and continued to lead the way after overhauling Sainz, who had gone top, before Norris — his McLaren this year powered by a Mercedes engine — took control only to be beaten by Verstappen in 1:30.847.
With 15 minutes remaining, there was less than a second separating the top 15 cars – a sure sign that the teams are tantalisingly close in basic performance, including Fernando Alonso down in 15th, in the final season under the current regulations.
On top of that, there were four different cars in the top four positions as the session drew to a close – evidence that a close fight is in prospect this weekend.
2nd session times:
Max Verstappen (NED/Red Bull-Honda) 1:30.847, Lando Norris (GBR/McLaren-Mercedes) 1:30.942. Lewis Hamilton (GBR/Mercedes) 1:31.082, Carlos Sainz (ESP/Ferrari) 1:31.127, Valtteri Bottas (FIN/Mercedes) 1:31.218, Daniel Ricciardo (AUS/McLaren-Mercedes) 1:31.230, Yuki Tsunoda (JPN/AlphaTauri-Honda) 1:31.294, Lance Stroll (CAN/Aston Martin-Mercedes) 1:31.393, Pierre Gasly (FRA/AlphaTauri-Honda) 1:31.483, Sergio Pérez (MEX/Red Bull-Honda) 1:31.503, Esteban Ocon (FRA/Alpine-Renault) 1:31.601, Charles Leclerc (MON/Ferrari) 1:31.612
Antonio Giovinazzi (ITA/Alfa Romeo-Ferrari) 1:31.740, Sebastian Vettel (GER/Aston Martin-Mercedes) 1:31.769, Fernando Alonso (ESP/Alpine-Renault) 1:31.770, Kimi Raikkonen (FIN/Alfa Romeo-Ferrari) 1:31.862, George Russell (GBR/Williams-Mercedes) 1:32.331, Mick Schumacher (GER/Haas-Ferrari) 1:33.297, Nicholas Latifi (CAN/Williams-Mercedes) 1:33.400, Nikita Mazepin (RUS/Haas-Ferrari) 1:33.449