Ferrari junior Callum Ilott strengthened his position at the head of the Formula 2 drivers' standings with his third pole position of the 2020 season at Barcelona.
llott was second-fastest in the opening runs of the 45-minute session, falling just 0.025s shy of the early benchmark set by Prema's Robert Shwartzman.
The British driver was shuffled down to third by UNI-Virtuosi team-mate Guanyu Zhou, who took advantage of an empty track after the opening runs to go second-fastest with a time just 0.014s shy of Shwartzman.
Ilott decided to begin his second run early, and managed to pull a huge gap on the rest of the field with a lap of 1m28.381s to go nearly half a second clear.
Shwartzman couldn't respond on his own second run and fell 0.183s short of a maiden pole, albeit securing his first F2 front-row start to continue his impressive start to his rookie F2 campaign thanks to feature race wins at the second Red Bull Ring round and Hungaroring round.
Zhou looked as if he would threaten his team-mate's provisional pole as he again had the track almost to himself for his final flyer, going fastest of all in the first sector.
However, the Renault junior lost ground later in the lap and came up 0.220s shy of Ilott meaning he slotted into third place ahead of tomorrow's feature race.
Joining Zhou on the second row for Saturday's opening race will be MP Motorsport driver Felipe Drugovich, while Mick Schumacher (Prema) and Yuki Tsunoda (Carlin) will make up row three.
Jack Aitken was seventh for Campos, ahead of practice pacesetter Dan Ticktum (DAMS), Nikita Mazepin (Hitech) and Louis Deletraz (Charouz).
ART Grand Prix's difficult weekend continued with Christian Lundgaard, who is currently second in the drivers' standings and just two points ahead of Shwartzman, qualifying down in 14th with team-mate Marcus Armstrong further back in 19th.
It means Lundgaard, who goes into the Barcelona feature race facing a deficit of 23 points to championship leader Ilott.
Barcelona F2 starting grid
|2||Robert Shwartzman||Prema Racing||0.183s|
|4||Felipe Drugovich||MP Motorsport||0.386s|
|5||Mick Schumacher||Prema Racing||0.508s|
|7||Jack Aitken||Campos Racing||0.598s|
|9||Nikita Mazepin||Hitech Grand Prix||0.652s|
|10||Louis Deletraz||Charouz Racing System||0.818s|
|11||Artem Markelov||BWT HWA RACELAB||0.916s|
|14||Christian Lundgaard||ART Grand Prix||0.952s|
|17||Pedro Piquet||Charouz Racing System||1.143s|
|18||Nobuharu Matsushita||MP Motorsport||1.260s|
|19||Marcus Armstrong||ART Grand Prix||1.305s|
|20||Luca Ghiotto||Hitech Grand Prix||1.309s|
|21||Giuliano Alesi||BWT HWA RACELAB||1.367s|
|22||Guilherme Samaia||Campos Racing||1.712s|