Coco Gauff didn't hold back on her emotions in the first day of the 2023 US Open. An incensed Gauff approached chair umpire Marijana Veljovic in the third set of her first-round match with Germany's Laura Siegemund on Monday.

Gauff thought Siegemund was taking way too long in her serves. The former approached Veljovic with a deuce in the fourth game of the third set. Gauff was leading the third set 3-0 at that point.

“She's never ready when I'm serving. She went over the clock like four times (and) you gave her a time violation once. How is this fair?” Gauff was overheard saying on the ESPN broadcast.

“No! You're calling the score after the point is over. It's not like we're playing love-point. You're calling the score like six seconds after the play is over…You missed her like four times. She's never ready. It's not like we're having 30-ball rallies. It's two balls,” Gauff continued.

Coco Gauff told Veljovic she had kept her emotions in check until that point. However, she couldn't contain herself any longer. The pro-Gauff crowd at Arthur Ashe Stadium applauded while she pleaded her case in the third set.

For his part, Gauff's coach Brad Gilbert shook his head at how long it took Veljovic to take action against Siegemund. Gauff eventually beat Siegemund in three sets 3-6, 6-2, 6-4.

Gauff taking a stand reflected the warrior mentality she displayed in her first-ever career victory over World No. 1 seed Iga Swiatek at the Cincinnati Open August 20. She eventually beat Karolina Muchova in the final to earn her first WTA 1000 title.

It's only the first day of the 2023 US Open but the drama has already reached fever-pitch proportions. Will Coco Gauff win her first Grand Slam title? Stay tuned.