Kamui Kobayashi had the final say in second pre-season test in Barcelona as the Sauber driver posted the quickest time on Friday.
The Japanese driver's 1:22.312, which was done on the super soft Pirellis, was the quickest time of the week, just eclipsing the 1:22.391 that Pastor Maldonado set on the penultimate day at the Circuit de Catalunya.
Kobayashi, who set his time in the morning session, was also the busiest driver on the track and completed 145 laps despite having an exhaust problem earlier in the day.
"It was another positive test day for us," said Sauber's head of track engineering Giampaolo Dall'Ara.
"We started in the morning with some further aero comparisons and set-up work. Before lunch Kamui did qualifying runs. Qualifying was actually a weakness of ours in the last two seasons and we have to resolve this. This obviously requires proper practice."
Williams' Maldonado also finished the test strongly as his best effort was just 0.249 shy of Kobayashi's time while Paul di Resta, who had an off-track excursion in his VJM05 in the morning, claimed P3 with a 1:23.119.
Jenson Button led the way of the so-called "big teams" as he was fourth fastest, but the Ferrari of Felipe Massa and Mark Webber of Red Bull were hot on his heels.
Nico Rosberg, who completed a full race simulation in the morning, was P8 with 1:23.843.
Heikki Kovalainen propped up the standings with a 1:26.968, but it was a frustrating day for Caterham as they lost more than two hours' running time after engineers "found an electrical issue with the engine which requires an engine change".
Marussia had an even worse day as rookie Charles Pic failed to make it onto the track due to a problem with the MVR-02.
"The issue centred around a damaged suspension component to the right rear corner of the car," a statement on their website read.
"The team spent the morning inspecting the part and trying to understand how the damage had occurred.
"A replacement part was available but the team were not happy to send the car out whilst proof-testing was still ongoing back at the Marussia Technical Centre in the UK and conclusive results would not have been achieved in time for any significant running to take place."
1. K Kobayashi Sauber 1:22.312 145 laps
2. P Maldonado Williams 1:22.561 +0.249 134
3. P di Resta Force India 1:23.119 +0.807 101
4. J Button McLaren 1:23.200 +0.888 115
5. F Massa Ferrari 1:23.563 +1.251 103
6. M Webber Red Bull 1:23.774 +1.462 85
7. J Vergne Toro Rosso 1:23.792 +1.480 92
8. N Rosberg Mercedes 1:23.843 +1.531 139
9. H Kovalainen Caterham 1:26.968 +4.656 70