Porsche's Jani tops final session on first day of WEC test at Monza

The four factory LMP1 cars each managed one quick lap before rain arrived just after the start of the two-hour night session, with the Swiss driver's 1m31.666s standing as the best.

Earl Bamber was second fastest in the sister Porsche 919 Hybrid a tenth and a half in arrears on a 1m31.823s.

Kazuki Nakajima set the best Toyota time with a 1m31.970s aboard the #8 TS050 HYBRID, which was half a second up on team-mate Kamui Kobayashi's fastest lap in the #7 car.

Nakajima subsequently set the fastest times in each of the first two sectors before losing out over the final third of the lap as the rain arrived.

All four factory P1s returned to the track after the rain drenched the Monza circuit, but were only able to lap in the mid-1m40s.

Mike Conway's second-session best of 1m31.332s for Toyota stood as the fastest time of the first day of the so-called prologue.

The ByKolles ENSO CLM-Nissan P1/01 made it out on track for the first time of the test so far after its built was completed in the pits, with Oliver Webb completing six laps in the wet.

Mathias Beche was the only LMP2 runner to set a flying lap in anything resembling dry conditions, his 1m41.467s aboard the #13 Rebellion ORECA-Gibson 07 some four seconds shy of team-mate Bruno Senna's class best in the morning session.

The two GTE Pro Porsches and one Ford and one Aston Martin all took to the track in the wet conditions.

Kevin Estre ended up at the top of the class times aboard the #92 Porsche RSR on a 1m58.247s, which put him over two seconds up on team-mate Frederic Makowiecki in the sister car.

The Gulf Racing Porsche was the only GTE Am car to set a time, Ben Marker ending up fastest on a 2m02.640s.