A huge upset went down Tuesday at the Ariake Tennis Park as Japan's world No. 2 tennis player, Naomi Osaka, was ousted from competition in a loss to the Czech Republic's Marketa Vondrousova, 6-1, 6-4.
Osaka looked nervous and played loose from the start, down four games in less than 15 minutes. The four-time Grand Slam champion -- who lit the Olympic cauldron just days ago -- then won her first service game, but ended up losing the set 6-1 in just 24 minutes.
Something clicked during a long rally at the top of the second set, and Osaka quickly broke serve to win two straight games. The match then became a roller coaster as Vondrousova battled back to even the score, and the opponents began trading games while holding serve. Throughout the match, Osaka stood far behind the baseline and missed a number of the Czech's signature drop shots.
Up 5-4 in the second, Vondrousova managed to break Osaka's serve one more time -- and win the match.
It was yet another surprise tennis loss following World No. 1 Ashleigh Barty's shocking first round ouster. The highest-ranking women's singles player remaining is Ukraine's Elina Svitolina, the fourth seed.