World No. 1 Novak Djokovic was the first to congratulate Jannik Sinner Friday on playing a “flawless match” when the Italian became the first player to defeat the Serbian beyond the quarterfinal stage of the Australian Open.

Sinner’s incredible display saw Djokovic go without a break point chance in a completed Grand Slam match for the first time in his career, per Tennis Abstract.

While the 10-time event winner praised what his opponent brought to their semifinal, Djokovic was equally frank about his own performance.

“I was, in a way, shocked with my level, you know, in a bad way. There was not much I was doing right in the first two sets,” Djokovic told press following the 6-1, 6-2, 6-7 (6), 6-3 defeat.

“I guess this is one of the worst Grand Slam matches I’ve ever played. At least that I remember. Not a very pleasant feeling playing this way. But at the same time, credit to him for doing everything better than me, in every aspect of the game.”