Raikkonen, who took the chequered flag in the season-opening race in Australia five days ago, supervise to gash the Red Bulls at the top of the timesheet at the finish of the opening 90-minute session at the Sepang International Circuit.
Mark Webber appear quickest with a lap of one minute 36.935secs at a track where temperatures are the newest faced by the squad this year at 32 degrees centigrade.
Raikkonen, conversely, had to wait until 30 minutes before the end of the session before choose to set his first timed lap, and was on the rapidity from the word go, but only after Lotus had been required to replace his KERS battery.
But straight away the 33-year-old slotted in following Webber, finishing 0.068secs drifting of the Australian who finished a unsatisfactory sixth in his home race on Sunday.
Webber, who started on the front row in Melbourne flanking world champion team-mate Sebastian Vettel, suffered an ECU malfunction prior to the installation lap that negotiation his start and from which he unsuccessful to sufficiently recover.