Sebastian Vettel beat four-time Formula 1 world champion Lewis Hamilton to the quickest time in first practice for the Abu Dhabi Grand Prix.
The Ferrari driver clocked a 1m39.006s on the ultrasoft Pirelli tyres to end the 90-minute session 0.120 seconds clear of Hamilton at Yas Marina.
Hamilton was the early pace-setter, clocking a 1m41.135s on the soft tyres, with teammate Valtteri Bottas focusing on the supersoft tyres.
Raikkonen, whose Ferrari featured a Red Bull-style diffuser as part of the team's experiments for 2018, then went quickest on the ultrasofts.
The Finn improved again to a 1m39.741s, but was then demoted as Hamilton and Bottas fitted the ultrasoft tyres just before the halfway mark.
Bottas was the first to cross the line, moving to the top of the pile with a 1m39.741s, but Hamilton beat that by an impressive 0.615s.
Verstappen's first effort on the ultrasofts was just a fraction off Hamilton's pace, but both were bumped down when Vettel did his ultra-soft run.
Bottas ended the session fifth quickest, ahead of Force India's Sergio Perez, who was 1.287s off the pace.
Fernando Alonso didn't set a laptime until the second half of the session, with the McLaren driver slotting straight into the top 10 on the ultrasoft tyres.
He ended up seventh, 1.516s off the pace and just 0.037s ahead of McLaren teammate Stoffel Vandoorne in eighth.
Felipe Massa, contesting his final F1 grand prix weekend, was ninth for Williams with Red Bull's Daniel Ricciardo rounding out the top 10.
Mercedes protege George Russell borrowed Esteban Ocon's Force India for FP1 and ended up 11th fastest, eight tenths adrift of Perez.
Antonio Giovinazzi was the other non-race driver to take part in the session, with the Italian running in place of Kevin Magnussen and going 18th quickest.
Renault's Carlos Sainz and Nico Hulkenberg were down in 15th and 17th respectively, but they did not run the ultrasoft tyre.
|3||Max Verstappen||Red Bull||TAG||15||1'39.154||0.148|
|6||Sergio Perez||Force India||Mercedes||24||1'40.293||1.287|
|10||Daniel Ricciardo||Red Bull||TAG||29||1'40.773||1.767|
|11||George Russell||Force India||Mercedes||26||1'41.131||2.125|
|14||Pierre Gasly||Toro Rosso||Renault||29||1'41.646||2.640|
|15||Carlos Sainz Jr.||Renault||Renault||23||1'41.748||2.742|
|20||Brendon Hartley||Toro Rosso||Renault||35||1'42.585||3.579|