Casper Ruud believes his 50th Tour-level victory of 2024 was one of his best after he upset third seed Carlos Alcaraz in his opening match of the ATP Finals on Monday.

Ruud, who had registered just two wins since the US Open, sealed a 6-1 7-5 win in just 86 minutes against Alcaraz for his maiden Top 3 triumph on hard courts.

The Norwegian reeled off five consecutive games from 1-1 to claim the first set at a canter but had to battle from the brink to secure a straight-set victory in Turin.

Alcaraz had raced into a 5-2 lead in the second set but was unable to hold on, with Ruud roaring back to sit top of the early standings in the John Newcombe Group.

"It's only one match, but it's one of the best wins of the season in terms of who I am playing and his ranking," Ruud said.

"I feel really happy, of course. I think we have seen Carlos play better tennis, but I took care of my chances.

"I haven't been boosting with confidence in the last few months so it was a great win for me and I would like to get some more wins in Turin.

"I got a good start, I got a break early and in the second set I managed to turn it around with some good tennis at the end."

Ruud will next seek to earn a second win on Wednesday when he will face either Alexander Zverev or Andrey Rublev, who play later on Monday.

Data Debrief: Ruud awakening

Although Alcaraz appeared below his physical best during Monday's encounter, Ruud took full advantage to continue his impressive streak against the very best in the world.

The Norwegian's latest win saw his record against players in the Top 10 of the ATP rankings improve to 5-2, and he was a worthy winner in Turin.

Ruud converted all four of the break points he was presented with, ending the contest with 10 unforced errors compared to Alcaraz's 26.