Alex Albon clocked in with the fastest time in the first practice session for the Brazilian Grand Prix, but the Red Bull charger concluded his wet morning in the wall while attempting a final run on slick tyres as track conditions improved.
Mercedes Valtteri Bottas was second in the 90-minute session that was run under wet-to-mixed conditions, with most drivers setting their best time on intermediate tyres.
The Finn preceded Ferrari's Sebastian Vettel and Charles Leclerc, while McLaren Carlos Sainz rounded off the top five.
The skies had opened over Sao Paulo early on Friday and showed no signs of clearing when it was time for drivers to kick off the action at the start of FP1.
There was therefore only limited running at the outset on a track that was saturated with water.
The Ferrari pair of Vettel and Leclerc bravely popped out of the Scuderia's garage for an exploratory lap before heading back to base.
Others followed suit, testing the stagnant waters, but efforts remained tentative at best. McLaren's Carlos Sainz was the first driver to put a time on the board, albeit one that was 14 seconds off the pace from last year's dry FP1 session.
Leclerc popped to the top of the timesheet with a 1m21.259s while in the Mercedes camp, Hamilton emerged on the pitlane, his Silver Arrows shod with a set of intermediates.
That choice perhaps enticed Leclerc to swap his wets for inters, the Monegasque banging in a 1m17.285s to go fastest by almost 5 seconds!
The first driver to close in on Leclerc was Renault's Nico Hulkenberg, also on inters, who clocked in 1.7s behind the Ferrari charger.
Getting better acquainted with the treacherous conditions, Vettel overhauled his teammate with a 1m17.041s. The German was then seen slowing suddenly exiting the Senna S, before picking up the pace once again.
With thirty minutes left on the session's clock, Bottas put Mercedes ahead for the first time, laying down a 1m16.693s that was three tenths faster than Vettel, who was followed by Leclerc, Sainz, Hulkenberg and Ricciardo who rounded off the top six.
After spending the first sixty minutes observing proceedings, Red Bull finally sent out Alex Albon, the British-Thai racer running on inters but taking advantage of the improving track conditions to put himself at the head of the field, beating Bottas' best by half a second.
The final ten minutes saw a flurry of activity as a number of drivers bolted on the soft dry tyre. Among those was Verstappen, but the Dutchman spun at the first corner, although he remained out of harm's way.
The same could not be said however for his teammate, with Albon bringing out the session to a premature end when losing it while coming over the hill at Turn 13 and thumping the tyre wall, albeit at relatively slow speed.
It was therefore a high and low for the F1 rookie who topped FP1 but concluded his morning with a ride back to the pits in the medical car!
Overall, Albon led Bottas, Vettel, Leclerc while Sainz was best of the rest from Hulkenberg, Ricciardo, Pierre gasly, Daniil Kvyat and Lando Norris.