The two Italians faced off after upsetting the No. 1 and No. 2 seeds.
On Tuesday evening, Serena defeated Venus and Djokovic prevailed against Lopez to advance.
The quarterfinals begin without Andy Murray, who exited the tournament in an upset Monday.
As the tournament enters its second week, temperatures remain high and the stakes get higher.
A record number of players have already had to retire from the tournament.
A startling comeback and a calendar grand slam may be in the cards.
The Swiss tennis player is a transcendent moral force in a world of blood, sweat and brute effort according to his fans