Novak Djokovic was delighted with the way he served against Sebastian Korda in the quarterfinal of the Miami Open on Thursday. The Serbian bested the American by 6-3, 7-6(4) in a quarter-final clash that was postponed from Wednesday.

Djokovic had a win percentage of 84 on his first serve and he was able to bring his A-game to the court against the local lad. The Serbian also smashed 11 aces in the match, which he wrapped up in one hour and 22 minutes.

With this win, Djokovic also became the oldest ATP Masters 1000 semi-finalist at 37 years and 10 months. Djokovic broke Roger Federer’s record, who reached the last four in Indian Wells and Miami at 37 years and seven months in 2019.

“As good as one can feel about his serve,” Djokovic said when reflecting on making 83 percent of his first serves. “Unbelievable serving the whole tournament, I’ve been serving really well. Especially today and I needed it because Sebastian in the second set was just making me run and he was playing really well from the back of the court, maybe not making as many errors like in the first set.”

Meanwhile, Korda was able to put himself in front as he was leading 0-3, 0-30 but Djokovic was able to serve his way out of trouble.

“It took some serves to get out of trouble. I was 0-3, 0/30 down, had some good serves and put myself in a position to [break back], which I did,” Djokovic said. “Tie-break could have been anybody’s game, but again, serve got me out of trouble. 5/4, serve winner. 6/4, ace to finish the match. I’ll take that as a highlight from the match today.”

Djokovic will face Grigor Dimitrov in the semifinal clash.