Team Mugen's Yamamoto's time of 1m12.902s in the afternoon session put him on top of the timesheets on Thursday, after the morning session was headed by Team Impul's Joao Paulo de Oliveira.

The Brazilian's time of 1m13.228s still kept him in second place overall, with former Williams F1 driver Kazuki Nakajima completing the top three, having set his best time in the afternoon session.

The Toyota factory driver then ended up fastest on a wet-dry Friday with a time of 1m13.368s ahead of TOM'S teammate Andre Lotterer - the German having been fifth on the first day.

De Oliveira was third, while ex-F1 star Kamui Kobayashi ended fourth, after having shrugged off a crash on Thursday.

McLaren reserve Stoffel Vandoorne finished fourth on Day 1, before he was called to Bahrain to substitute for the injured Fernando Alonso, with the Belgian set for his F1 debut this weekend.

British racer James Rossiter was seventh and 18th respectively, while Indian Narain Karthikeyan finished 12th on both days with Team LeMans.

The second day's rain-affected first session saw as many as nine red flags. 2015 champion Hiroaki Ishiura was quickest on the wet track.

Full Day 1 results:

Po. Driver Team / Engine Time (AM) Time (PM) 1 Naoki Yamamoto TEAM MUGEN

HONDA HR-414E 1'13.555 1'12.902 2 Joao Paulo de Oliveira ITOCHU ENEX TEAM IMPUL

TOYOTA RI4A 1'13.228 1'13.394 3 Kazuki Nakajima VANTELIN TEAM TOM’S

TOYOTA RI4A 1'13.752 1'13.330 4 Stoffel Vandoorne DOCOMO TEAM DANDELION RACING

HONDA HR-414E 1'14.291 1'13.352 5 Andre Lotterer VANTELIN TEAM TOM’S

TOYOTA RI4A 1'13.466 1'13.593 6 Tomoki Nojiri DOCOMO TEAM DANDELION RACING

HONDA HR-414E 1'13.564 1'14.040 7 James Rossiter KONDO RACING

TOYOTA RI4A 1'15.240 1'13.622 8 Kamui Kobayashi SUNOCO Team LeMans

TOYOTA RI4A 1'14.566 1'13.643 9 Bertrand Baguette NAKAJIMA RACING

HONDA HR-414E 1'13.644 1'13.647 10 Yuhi Sekiguchi ITOCHU ENEX TEAM IMPUL

TOYOTA RI4A 1'14.623 1'13.663 11 Koudai Tsukakoshi REAL RACING

HONDA HR-414E 1'14.146 1'13.700 12 Narain Karthikeyan SUNOCO Team LeMans

TOYOTA RI4A 1'14.483 1'13.727 13 Hiroaki Ishiura P.MU / CERUMO · INGING

TOYOTA RI4A 1'14.439 1'13.789 14 Yuji Kunimoto P.MU / CERUMO · INGING

TOYOTA RI4A 1'13.873 1'14.074 15 Takashi Kogure DRAGO CORSE

HONDA HR-414E 1'13.893 1'14.692 16 Takuya Izawa REAL RACING

HONDA HR-414E 1'14.760 1'14.021 17 Yuichi Nakayama KCMG

TOYOTA RI4A 1'14.278 1'14.242 18 William Buller KONDO RACING

TOYOTA RI4A 1'14.543 1'14.996 19 Daisuke Nakajima NAKAJIMA RACING

HONDA HR-414E 1'14.783 1'14.626 20 Hideki Mutoh Honda Test Car

HONDA HR-414E 1'19.456 1'15.122

Full Day 2 results: