In the two hour, 15 minute match, the Canadian teenager fought back from a set and a break down for the second straight match to knock out a former champion. The world number 73 will face fifth seed Elina Svitolina in the quarterfinals.
Fernandez stuns second straight Grand Slam champion to reach first Slam quarterfinal
The match began with each player breaking serve, Fernandez losing hers after leading 40-15 in the game. After the Canadian took a 4-2 lead, Kerber reeled off four consecutive games.
A forehand dumped into the net put the German back on serve and she broke Fernandez to love with a sparkling backhand winner into the corner. Serving for the set at 5-4, the 2016 champion held to love.
It all seemed to be going Kerber's way when Fernandez overhit a forehand to give the German a 2-1 lead in the second set. The world number 73 would eventually break back on her only chance of the set to even the score at 4-4.
After Kerber saved a set point trailing 6-5, the set would end up in a tiebreaker. The decisive moment came when Fernandez struck a forehand winner down the line to bring up double set point and two points later, she closed out the set to level the match.
The third set began with both players saving a break point early on until the Canadian broke after Kerber sailed a forehand long. A second break gave Fernandez the opportunity to serve for the match at 5-2 and she closed things out when the German sliced into the net.