Daniil Medvedev had a meltdown on the court at Louis Armstrong Stadium Sunday night at the U.S. Open in his loss against Benjamin Bonzi.

Daniil Medvedev's comeback attempt comes up short as Benjamin Bonzi prevails for a first-round victory at the US Open.

Day two of the US Open delivered the tournament’s first big stunner. Renata Zarazúa of Mexico defeated No. 6 seed Madison Keys 6-7(10), 7-6(3), 7-5 in a major first-round upset at Arthur Ashe Stadium Monday afternoon.

Australian Open champion Madison Keys was undone by 89 unforced errors and was upset in the first round of the U.S. Open by Renata Zarazua of Mexico.

Australian Open champion Madison Keys suffered a shock first-round defeat against Mexico’s Renata Zarazua amid searing heat at Arthur Ashe Stadium on Monday afternoon. Keys, the world No. 6, made a staggering 89 unforced errors in a marathon match against the 95th-ranked Zarazua,