Oscar Piastri blasted in F1 title race battle with Lando Norris: 'Reached his limit'

That triumph extended his lead over Norris and marked an impressive run of seven wins from the opening 15 rounds.

However, the subsequent five races have witnessed a complete reversal of fortunes.

Piastri has failed to secure a victory since Zandvoort and hasn't reached the podium in the past four events, enabling Norris to seize the championship lead following his commanding performance in Mexico City last weekend.

Former world champion Jacques Villeneuve believes Piastri has been performing at his maximum capability whilst his team-mate has found another gear.

Speaking to Sky Sports' The F1 Show, Villeneuve questioned whether Piastri's early-season superiority was genuine or merely a reflection of Norris struggling with the car.

"We didn't have an extremely fantastic Lando early in the season, not the Lando we had at the end of last year," Villeneuve explained.

"And we kept saying, 'oh, that's because Piastri has stepped up, he's now on Lando's pace and even quicker.'"

The Canadian suggested this dynamic may have bred complacency in Piastri. "When all you have to fight is your team-mate, maybe you don't push to that last limit, that last tenth of a second," he said.

Villeneuve's stark assessment was that whilst "Lando is driving faster and better than he's been all season," Piastri cannot match this improvement because he "was already at his limit."

A series of costly mistakes have marked Piastri's dramatic downturn. The Azerbaijan Grand Prix weekend proved particularly catastrophic, with the Australian crashing during both qualifying and the race, whilst also committing a jump start infringement.

This disastrous Baku performance ended an impressive streak of consistency.

Following a ninth-place finish in the season opener after spinning in wet conditions, Piastri had secured top-four finishes at the subsequent 15 races, missing the podium on just two occasions.

The errors continued in Austin, where an ill-judged overtaking attempt resulted in contact that eliminated both McLaren drivers from the Sprint race.

Since Azerbaijan, Piastri has managed only fourth place in Singapore and fifth-place finishes in both Austin and Mexico City, allowing Norris and Max Verstappen to consistently outscore him over the past five race weekends.

Sky Sports F1's Martin Brundle believes the Azerbaijan weekend inflicted lasting psychological damage on Piastri.

"Baku would have scattered his brain," Brundle told Sky Sports' The F1 Show. "That was a very difficult weekend for him with twice in the barriers and the jump start and it seems to have gone off the rails."

Brundle observed a fundamental shift in Piastri's demeanour. "Something's happened in Oscar's head," he noted, questioning whether similar patterns existed in the driver's junior career.

The veteran commentator highlighted how Piastri's trademark composure has vanished.

He said: "We described him as horizontal for pretty much all the season because that's how he looked. He always has been so calm on the radio, not letting things get to him.

"And suddenly, that glass ceiling, that facade, whatever it is, seems to have gone from him and he's struggling."

Villeneuve provided insight into the psychological spiral affecting drivers who attempt to exceed their limits.

"When you drive within the limit, the car is perfect. It's easy, you drive, you save your tires. And suddenly, you have to go a couple of tenths faster. You can't drive the car anymore. Everything is wrong," he explained.

"You drive tensed up, nothing works, and that's it. It gets in your head. And you just get slower and slower and slower, and you start inventing setups that don't exist."

Brundle dismissed suggestions of team favouritism, emphasising McLaren's commitment to both drivers. "Rest assured, a team doesn't spend $400m a year and have 1,500 employees and try to make one of their cars go a little bit more slowly," he stated.