'Tomorrow's going to be a challenge, I've never driven this car in the rain.'
The final phase of qualifying was halted, with only Piastri and Haas' Nico Hulkenberg having set times, when Sainz slammed backwards into the barriers at the final corner as he prepared to start his flying lap.
Red Bull's double World champion Max Verstappen won the Mexico City Grand Prix on Sunday to set a Formula One record of 14 victories from a single season, as well as the most points scored.
McLaren's Lando Norris dominated the Singapore Grand Prix from start to finish on Sunday to take another chunk out of Max Verstappen's Formula One championship lead.
Verstappen leads seven times world champion Hamilton by six points with six races remaining and the pole at Austin's Circuit of the Americas was the ninth of the season for the Dutch 24-year-old -- and eighth in the last 11 races.
Hamilton held on for fourth, but slipped from 18 to 32 points behind Verstappen in the championship standings.
Red Bull closed the gap to champions Mercedes in the constructors' standings to one point.
McLaren are leading the constructor's championship but are only 29 points ahead of Ferrari, with Leclerc an obvious threat and team mate Carlos Sainz qualifying fifth and Mercedes' George Russell sixth.
Max Verstappen put his Red Bull on pole position for the Austrian Grand Prix
Seven times world champion Lewis Hamilton hunted down Max Verstappen to win the Sao Paulo Grand Prix for Mercedes on Sunday and slash his Red Bull rival's Formula One lead to 14 points in one of the greatest drives of his career.
Hamilton decided to take matters into his own hands and pass several cars ahead of him, without gaining anything as Verstappen's time stood the test.
Hamilton's team mate Valtteri Bottas finished third, ahead of Ferrari's Charles Leclerc, in a race aimed at providing more thrills for fans over the three days of track action and potentially shaking up the starting grid.
Red Bull's Mexican Sergio Perez was a distant third, struggling with dehydration after a water bottle failure in the Texas heat.
Carlos Sainz completed a double race distance for previously struggling Williams and pushed his Ferrari successor Lewis Hamilton off the top of the testing
Mondo Duplantis was named the Laureus World Sportsman of the Year, while American gymnast Simone Biles bagged the top women's honour at the Laureus World Sports Awards.
McLaren's Australian Daniel Ricciardo will join the Dutch 23-year-old on the front row for the first time since the pair were team mates at Red Bull in 2018.
Mercedes' George Russell celebrated a surprise Austrian Grand Prix win on Sunday after Red Bull's triple world champion Max Verstappen and McLaren's Lando Norris collided late in the race
McLaren could clinch their first constructors' crown since 1998 on Sunday if they outscore Ferrari by 21 points at the Qatar F1 Grand Prix.
Lewis Hamilton will bring down the curtain on his Mercedes career in Abu Dhabi on Sunday as his past and future Formula One teams, McLaren and Ferrari, fight for a constructors' title to end years of waiting.
Drivers returned to the pits, under a darkening sky, with engineers using torches in the garages before back-up generators came on and the session resumed about an hour later.
Former Ferrari technical director Ross Brawn says 70th Anniversary race winner Max Verstappen reminds him of Formula One great Michael Schumacher. Brawn masterminded Schumacher's seven world championships with Benetton (1994 and 1995) and Ferrari (2000-04) and was team boss at Mercedes when the German made his comeback from 2010-2012.
Lando Norris roared to his second successive pole position, and third in four races, in a McLaren front row sweep with team mate Oscar Piastri
Formula One leader Max Verstappen passed Mercedes rival Lewis Hamilton on the penultimate lap to win a tense French Grand Prix for Red Bull on Sunday and canter 12 points clear at the top.
IMAGES from the Azerbaijan F1 Grand Prix held at Baku City Circuit on Sunday
Hyundai's French rally driver Adrien Fourmaux was handed a 10,000 euro fine, with another 20,000 suspended, in Sweden on Sunday, however, for swearing in a live post-race broadcast interview.
Max Verstappen won the Spanish Grand Prix in a Red Bull one-two on Sunday
The pole was the second of the Dutch 22-year-old's Formula One career and the first in Brazil for engine partners Honda since the late triple champion Ayrton Senna in 1991 with McLaren.
Red Bull's Max Verstappen won Formula One's 70th Anniversary Grand Prix at Silverstone on Sunday to end Mercedes' run of domination and become champion Lewis Hamilton's closest challenger.
Red Bull are concerned about their constructors' title defence being weakened at a time when McLaren are emerging as a threat
Max Verstappen put Red Bull on pole position for Formula One's season-opening Bahrain Grand Prix on Saturday, with seven times world champion Lewis Hamilton alongside on the front row for Mercedes.
The times at the Istanbul Park circuit, hosting a Formula One race for the first time since 2011, were largely meaningless.
McLaren's Lando Norris took pole position for the Qatar Grand Prix sprint on Friday with Mercedes' George Russell denying the Formula One leaders a front row.
Red Bull's Max Verstappen won a wet and crazily chaotic German Grand Prix littered with crashes and safety car periods on Sunday with Mercedes' Formula One leader Lewis Hamilton failing to score.
Australian driver Oscar Piastri, 23, emerged victorious in his first ever Formula One race at the Hungarian Grand Prix on Sunday.
Max Verstappen won the season-ending Abu Dhabi Formula One Grand Prix from pole position for Red Bull on Sunday.
Red Bull's Max Verstappen won a chaotic and crash-halted Emilia Romagna Grand Prix at Imola on Sunday with Lewis Hamilton second for Mercedes and retaining the lead in the championship by a single point.
McLaren's Lando Norris took a commanding Dutch Grand Prix victory on Sunday.
Sebastian Vettel blamed Red Bull's Max Verstappen on Sunday for a Japanese Grand Prix tangle that dealt a huge blow to the Ferrari driver's fading Formula One title hopes.
Formula One championship leader Max Verstappen lifted himself into a league of his own as he beat title rival Lewis Hamilton to pole position with a blinding lap in qualifying for the French Grand Prix at Circuit Paul Ricard.
Rishabh Pant has been nominated for the prestigious Laureus World Comeback of the Year Award.
