Rookie Magnussen fastest on third day of Formula One testing
McLaren Mercedes' Danish driver Kevin Magnussen stops in the pits during the Formula One pre-season test days at Jerez racetrack in Jerez on January 30, 2014 - by Jorge Guerrero
Magnussen took over from teammate Jenson Button, who had gone fastest in the morning, for the afternoon session and bettered the Briton's mark with an effort of 1min 23.276 secs.
Williams' Felipe Massa was second fastest with Lewis Hamilton in third as the Mercedes continued to pile on the miles.
The Englishman didn't match teammate Nico Rosberg's mammoth 97 lap effort from Wednesday, but was the busiest man on the track as he went around 62 times.
By contrast, it was another frustrating day for Red Bull and their new driver Daniel Ricciardo as the Australian only managed three laps before the Austrian team called off their efforts early for a second consecutive day.
Red Bull have only completed 14 laps over the opening three days and seem well behind their title rivals with only nine more days testing to come before the season gets underway for real in Australia in March.
Another former champion Fernando Alonso also made his first appearance of the season in the Ferrari F14-T.
The Spaniard's arrival drew a much larger crowd than in the previous two sessions and Ferrari enjoyed another satisfactory day as Alonso finished fifth fastest after completing 58 laps.