Lewis Hamilton struggles to explain massive performance drop on final US GP lap

Hamilton's pace fell off dramatically on the last lap of the US GP in Austin – and it wasn't because he was easing off deliberately

Lewis Hamilton had a rather uneventful race at the United States Grand Prix until the final lap, when an unidentified problem cost him four seconds and put him under threat from Oscar Piastri.

After getting a good start that allowed him to move ahead of George Russell while keeping Piastri at bay on the outside of Turn 1, Hamilton spent some time as a privileged spectator to the battle between his team-mate Charles Leclerc and Lando Norris for second place.

However, as the race strategies unfolded, the seven-time world champion fell back into a kind of no man's land, positioned between that duo ahead and Piastri behind.

At the start of the final lap, Hamilton was nine seconds behind his team-mate and five seconds ahead of the Australian. Then, suddenly, the Ferrari driver began losing pace, tenths of a second at a time as the corners went by - until the gap to Piastri dropped below two seconds. Finally, just as the McLaren had the Ferrari within striking distance, Hamilton crossed the finish line with only a 1.1-second advantage.

When asked after the race by international media, including Motorsport.com, whether he had suffered a puncture, Hamilton replied:

"I don't really know. I was in Turn 5, and it felt like I hit something. All of a sudden, I had massive understeer, and I thought it was a puncture."

Lewis Hamilton in parc ferme after the US Grand Prix

Photo by: Zak Mauger / LAT Images via Getty Images

"I braked at Turn 11, and the car just wouldn't stop. I thought, ‘Damn, what's going on?' In the end, I managed to hold on through the final corners, but I had massive understeer. I thought the front wing was broken or that something had happened to a tyre. It was really close with Piastri."

Beyond this incident, which ultimately had no real consequences, the United States Grand Prix weekend was perhaps one of Hamilton's most complete of the season – he equalled his best grand prix result of the year on Sunday – despite still lacking the pace to genuinely fight for the podium, whether in the sprint or on race day.

"There's clearly a positive trend moving in the right direction - I feel much more comfortable in the car. I'm definitely going to take a serious look at all of this over the next few days to try to understand how we can get more out of the car and put it in a slightly better position."

Additional reporting by Stuart Codling