Suspicions that rain could play a major part in deciding the outcome of this year's Formula One world championship came closer to reality as the opening practice session at Monza was abandoned ahead of schedule as the Italian track flooded.
Rain started shortly after the session got underway, but intensified as time went on, causing a few on-track moments before the teams headed back to the sanctuary of their garages to ride out the storm.
The rain, now accompanied by thunder and lightning, continued however, and, with the track and surrounding areas gradually coming under water, the session was red-flagged five minutes short of its scheduled 1130hrs conclusion.
Force India's Adrian Sutil was thus declared quickest in session, having managed to post a decent lap before the conditions deteriorated. Rubens Barrichello and Giancarlo Fisichella completed the unlikely top three.
Despite Bridgestone doing sterling service in fitting enough wet and extreme wet tyres to cope with demand, the conditions quickly became so bad that the teams had nothing to learn by insisting that their drivers ventured out. Sutil was among those to spin on track as the surface accumulated more and more water, with fellow pacesetters Barrichello and Fisichella also being caught out, along with Toro Rosso's Sebastian Vettel, Renault's Nelson Piquet Jr and Toyota's Timo Glock.
Others had the foresight not to even complete a flying lap, with the two McLaren drivers - Heikki Kovalainen and Lewis Hamilton - joining BMW pair Robert Kubica and Nick Heidfeld, Kazuki Nakajima - who also spun on track - and Mark Webber in only running an exploratory out-lap. Ferrari's Felipe Massa and Kimi Raikkonen headed out just as conditions were worsening, and ran five laps apiece to wind up 14th and ninth respectively.
Behind Fisichella, the top was filled out by Glock, Nico Rosberg, Fernando Alonso, Sebastien Bourdais, Jarno Trulli, Raikkonen and Vettel, but the near five-second gap between the Germans that book-ended the order told its own story.
The session ended prematurely with power being lost in some sections of the circuit and water threatening to penetrate the garages, as well as leave the track awash. The second session of the day is due at 1400hrs local time, with practice and qualifying for the support events - including the GP2 Series showdown - also scheduled for day one.