The 2022 U.S. Open just got a little more interesting. The No. 2-ranked Rafael Nadal, who has already been crowned champion at this year's Australian Open and French Open, was shockingly upset in the Round of 16 at the US Open by 24-year-old American Frances Tiafoe in four sets (6-4, 4-6, 6-4, 6-3) on Monday.

Following the loss to Tiafoe, Nadal gave a very honest and succinct 10-word answer on why and how he failed to beat the less-accomplished American.

I played a bad match,” Nadal quipped to iPaper journalist James Gray following the loss. “He played a good match.”

The 36-year-old Nadal still appears to be recovering from the abdominal injury that forced him to retire from the semifinals in this year's Wimbledon. However, he didn't resort to any excuses following the match as he took credit for how poorly he played and gave credit to the young and up-and-coming Tiafoe.

This is Nadal's first defeat to an American at a grand slam tournament in 17 years. He last lost to James Blake in 2005.

Tiafoe might've known he was facing a less-than-100-percent Nadal in the Round of 16 as he was extremely confident heading into his showdown with one of the greatest tennis players of all time.

“I’m not going to have that first-time-playing-him, excited-to-play [feeling],” Tiafoe said prior to the match with Nadal. “Now I believe I can beat him.”

Tiafoe is now the youngest American tennis player to reach the US Open semifinals since Andy Roddick in 2004, according to the ATP Tour.

Tiafoe will next face ninth-ranked Andrey Rublev on Wednesday, September 7, in the quarterfinals while Nadal will need to take the time to get healthy following abdominal surgery.