Returning to the Sakhir circuit on Thursday for the final test, the same story unfolded with a Merc-powered runner quickest and Red Bull struggling to put in the laps.
Sergio Perez started the final pre-season test off on the right note as the Force India racer posted a 1:35.290 in his VJM07. That put him 0.894s up on Valtteri Bottas, who once again put in a marathon effort.
The Finnish racer, entering his second season in Formula One, covered 128 laps in his Williams FW34, the most he has done on a single day.
Kimi Raikkonen was third quickest for Ferrari on a day when the Scuderia stated they would be introducing their "main upgrades" for the season-opening Australian GP.
Raikkonen, who trialed a new front wing as part of the upgrades, was 1.142s off the pace and brought out a late red when he stopped on the back straight with just a few minutes remaining in the day's play.
Nico Rosberg was fourth quickest for Mercedes ahead of Adrian Sutil and Kevin Magnussen.
The McLaren rookie's 1:37.825 ensured that all the Mercedes-powered finished inside the top six on the day.
Meanwhile it was a day of mixed results for Red Bull Racing. While the team once again spent too much time behind the privacy screens instead of on the track, Daniel Ricciardo did at least post the team's fastest lap time.
The Aussie's 1:37.908 was a good seven-tenths up on Red Bull's previous best time during testing at the Sakhir circuit. He did, though, only complete 39 laps amidst reports that their current issues belong to the RB10 and not its Renault engine.
Max Chilton was eighth quickest ahead of Daniil Kvyat, Pastor Maldonado and Kamui Kobayashi.
It was a problematic day for Maldonado and Kobayashi who both brought out the red flags. Kobayashi's was in the first hour of the day while Maldonado broke down just before lunch. His exhaust issues meant he completed just 31 laps before "an early bath."
01 Sergio Perez Force India 1:35.290 105 laps
02 Valtteri Bottas Williams 1:36.184 +0.894 128 laps
03 Kimi Raikkonen Ferrari 1:36.432 +1.142 54 laps
04 Nico Rosberg Mercedes 1:36.624 +1.334 89 laps
05 Adrian Sutil Sauber 1:37.700 +2.410 89 laps
06 Kevin Magnussen McLaren 1:37.825 +2.535 109 laps
07 Daniel Ricciardo Red Bull 1:37.908 +2.618 39 laps
08 Max Chilton Marussia 1:38.610 +3.320 44 laps
09 Daniil Kvyat Toro Rosso 1:39.242 +3.952 56 laps
10 Pastor Maldonado Lotus 1:40.599 +5.309 31 laps
11 Kamui Kobayashi Caterham 1:42.285 +6.995 19 laps
Day One's Action In Bahrain