Jannik Sinner booked his spot in the quarter-finals at Indian Wells with a nervy straight-sets win over Joao Fonseca.

The second seed won 7-6 (8-6) 7-6 (7-4) in two hours and three minutes to set up a last-eight clash with Learner Tien.

Sinner won 92% of his first-serve points in the opening set, while Fonseca won 73% of such points as both players held their nerve with the ball in hand.

Nineteen-year-old Fonseca raced into a 6-3 lead in the tiebreak, but squandered all three set points before Sinner took the first.

The Italian then managed to convert the first break point of the match in the second to take a 4-2 lead, but Fonseca broke back to love in the ninth game as they headed for another tiebreak.

Fonseca briefly led at 4-3, but Sinner reeled off four straight points and clinched victory with his first match point.

Data Debrief: Sinner thrives in the USA

Since the start of 2024, Sinner is now 87-2 against opponents ranked outside the ATP top 20 – one loss came to the eventual champion (Alexander Bublik, Halle 2025) and the other via retirement (Tallon Griekspoor, Shanghai 2025).

And since the ATP Masters 1000 format's introduction in 1990, Sinner (84.6%, 33-6) holds the best combined win rate of any player at Indian Wells and Miami, surpassing Novak Djokovic (84.3%) - minimum 10 matches.