Louis Deletraz topped the first day of Formula 2's post-season test in Abu Dhabi for MP Motorsport, which also had the fastest time in GP3 testing earlier today.
Alexander Albon was second quickest for DAMS ahead of Norman Nato, who was driving for Racing Engineering.
With the majority of the field concentrating on long runs during the day's first F2 session - the series alternated with GP3 at the Yas Marina track - most of the drivers set their quickest times during the evening slot.
Deletraz - third quickest for MP in the first session - ended up with the best time of the day, a 1m48.282s, which was 0.802s quicker than the fastest time set by McLaren Formula 1 junior Lando Norris earlier on.
Albon wound up 0.045s adrift on his first time out for DAMS, with Nato's best time 0.23s slower than Deletraz.
Haas F1 junior Santino Ferrucci was fourth fastest for Trident, where he had closed out the second half of the 2017 F2 season after beginning the year racing for DAMS in GP3.
Nyck de Vries recovered from a morning session where he only completed four laps due to an engine problem, to post the day's fifth fastest time for his 2018 team, Prema Racing.
Norris finished the day in sixth place testing for Campos Racing, the team where he made his competitive F2 debut at the 2017 season finale in Abu Dhabi last weekend.
The McLaren F1 junior will race for Carlin in F2 in 2018, but with the British squad taking a sabbatical from the second-tier category this year he has continued to work with Campos.
George Russell - the 2017 GP3 champion for ART - finished the day in seventh for the French squad, ahead of 2017 Russian Time team-mates Luca Ghiotto and Artem Markelov in eighth and ninth - with the former testing for MP today.
Another Haas F1 junior, Jenzer Motorsport's GP3 race-winner Arjun Maini, rounded out the top 10 for Trident.
Jack Aitken, testing at the same venue where he clinched the 2017 GP3 runner-up spot last weekend, was 11th in the other ART car, with DAMS driver Nicholas Latifi separating him from Nirei Fukuzumi (third in 2017 GP3 standings), who was 13th fastest for Arden.
Day one morning times
|1||Lando Norris||Campos Racing||1m49.084s||-||27|
|2||Jack Aitken||ART Grand Prix||1m49.240s||0.156s||30|
|3||Louis Deletraz||MP Motorsport||1m49.378s||0.294s||14|
|6||George Russell||ART Grand Prix||1m49.434s||0.350s||30|
|7||Luca Ghiotto||MP Motorsport||1m49.505s||0.421s||16|
|8||Norman Nato||Racing Engineering||1m49.557s||0.473s||20|
|10||Artem Markelov||RUSSIAN TIME||1m49.796s||0.712s||26|
|12||Tadasuke Makino||RUSSIAN TIME||1m50.362s||1.278s||21|
|13||Nirei Fukuzumi||Arden International||1m50.387s||1.303s||24|
|15||Ralph Boschung||Arden International||1m50.719s||1.635s||24|
|16||Maximilian Gunther||Racing Engineering||1m51.228s||2.144s||20|
|17||Guan Yu Zhou||Rapax||1m51.318s||2.234s||19|
|18||Sean Gelael||Prema Racing||1m51.319s||2.235s||18|
|19||Luis Michael Dorrbecker||Campos Racing||1m51.932s||2.848s||30|
|20||Nyck de Vries||Prema Racing||2m09.204s||20.120s||4|
|1||Louis Deletraz||MP Motorsport||1m48.282s||-||15|
|3||Norman Nato||Racing Engineering||1m48.512s||0.230s||31|
|5||Nyck de Vries||Prema Racing||1m48.700s||0.418s||31|
|6||Lando Norris||Campos Racing||1m48.710s||0.428s||27|
|7||George Russell||ART Grand Prix||1m48.805s||0.523s||26|
|8||Luca Ghiotto||MP Motorsport||1m48.842s||0.560s||22|
|9||Artem Markelov||RUSSIAN TIME||1m48.848s||0.566s||29|
|11||Jack Aitken||ART Grand Prix||1m49.007s||0.725s||26|
|13||Nirei Fukuzumi||Arden International||1m49.300s||1.018s||27|
|14||Ralph Boschung||Arden International||1m49.531s||1.249s||32|
|15||Tadasuke Makino||RUSSIAN TIME||1m49.577s||1.295s||22|
|16||Sean Gelael||Prema Racing||1m49.799s||1.517s||30|
|17||Guan Yu Zhou||Rapax||1m49.803s||1.521s||25|
|19||Maximilian Gunther||Racing Engineering||1m51.638s||3.356s||10|
|20||Luis Michael Dorrbecker||Campos Racing||1m52.147s||3.865s||27|