Sergio Perez is starting to settle nicely into his role at McLaren with the Mexican topping the timesheets on day two in Barcelona.
The 23-year-old, who completed 97 laps on Wednesday, hit the front with a 1:21.848, in the afternoon while he focused on single flying laps on soft tyres. He is the only driver to have dipped under the 1:22 mark so far at the Circuit de Catalunya.
His time was 0.349s better than that of morning pacesetter Sebastian Vettel (also softs), but it was once again a case of the regulars dominating proceedings with Kimi Raikkonen of Lotus, Mercedes' Lewis Hamilton and Fernando Alonso from Ferrari completing the top five.
Vettel endured a mixed day at the office, posting the best time in the morning session but then being forced to spend some time in the garage late afternoon after a loose wheel following a pit stop forced him to stop.
The team, though, insist it wasn't a major issue and they will be back to their best on Wednesday.
Raikkonnen was third fastest with a 1:22.697, but he also had some reliability issues as a gearbox problem forced him to miss most of the morning action. He completed only 43 laps in the afternoon, but his time was good enough for third.
Hamilton was the busiest man on the track as he completed 121 laps, posting a best time of 1:22.726 on the hard tyres while Alonso was fifth with a 1:23.247.
1 Sergio Perez McLaren 1m21.848s 97 Soft
2 Sebastian Vettel Red Bull 1m22.197s +0.349 84 Soft
3 Kimi Raikkonen Lotus 1m22.697s +0.849 43 Medium
4 Lewis Hamilton Mercedes 1m22.726s +0.878 121 Hard
5 Fernando Alonso Ferrari 1m23.247s +1.399 76 Medium
6 Valtteri Bottas Williams 1m23.561s +1.713 98 Soft
7 Daniel Ricciardo Toro Rosso 1m23.718s +1.870 70 Medium
8 Paul di Resta Force India 1m23.971s +2.123 62 Medium
9 Nico Hulkenberg Sauber 1m24.205s +2.357 88 Medium
10 Max Chilton Marussia 1m25.115s +3.267 67 Soft
11 Charles Pic Caterham 1m26.243s +4.395 102 Medium