This is why they play the matches.

Garbine Muguruza was playing arguably the best tennis in the women's tennis world. She beat Serena Williams for her first major title at the French Open earlier this month and appeared poised for a strong performance at Wimbledon, where she was a finalist in 2015.

But her run came to a screeching halt on Thursday when the world's No. 2 player lost in straight sets to world No. 124 Jana Cepelova -- and it wasn't even close.

garbinemuguruza063016.jpg
Garbine Muguruza suffered a stunning loss in the second round of Wimbledon. USATSI

Cepelova won 6-3, 6-2, as Muguruza just never seemed to get started.

"My energy was missing a little today," Muguruza said. "From yesterday I felt a little bit tired. During the match and after the match, I'm like, 'Tough day today, empty today.'"

Cepelova has become something of a giant-slayer in recent tournaments. The Slovakian defeated No. 3 seed Simona Halep in the first round last year at Wimbledon, and beat top-ranked Williams in 2014.

"Last year I beat Halep on the same court and I had great memories," the 23-year-old Cepelova said. "I am so happy."