It was not a good day to be a top-seed at the Australian Open on Sunday as both Andy Murray and Angelique Kerber were defeated in Melbourne.

It was supposed to be a breeze into the quarterfinals for world no.1 Andy Murray. But Mischa Zverev did not get that memo as he upset the Scot 7-5, 5-7, 6-2, 6-4.  The 29-year old’s serve-and-volley tactics proved to be effective during the match as he won 65 points at the net.

Murray never appeared comfortable with Zverev’s constant net attack as frustration set in at times.

The loss was the earliest Murray has exited Melbourne in eight years. “I've had tough losses in my career in the past. I've come back from them. This is a tough one,” Murray said. “I'm sure I'll come back okay from it. But right now, I'm obviously very down because I wanted to go further in this event, and it wasn't to be.”

Zverev and Murray go back to their teen days where they competed against each other as juniors. Alexander was in attendance watching his older brother a day after a hard-fought five-set loss to Rafael Nadal.

On how he was successful, Zverev responded afterward, “I was like in a little coma, just serving and volleying my way through it. There were a few points where I didn't know how I pulled it off but somehow I made it,” he said.

Meanwhile, Murray’s wait to hoist the Australian Open championship trophy must wait another year. He has never won the tournament and has been runner-up to Novak Djokovic four times.

Elsewhere, the top-seeded woman met the same fate as Angelique Kerber lost to Coco Vandeweghe, 6-2 6-3.

The 25-year old American overwhelmed the defending champion who appeared helpless at times. She struck 30 winners while Kerber could only muster 7. Vandeweghe capitalized on 4 of her 6 break point opportunities.

“It's really special to play a number one player in the world on any stage. I believe it’s my first number one win so I’ll take that,” Vandeweghe said. “Last year I came here and I didn't even win a match and here I am now.”

After a routine first set for Vandeweghe, it appeared that the world no.1 would mount a challenge in the second as she earned an early break of service. But it took very little time for the Californian to tilt the set back into her favor as she finished by winning the last four games.

Kerber admitted that she did not play up to her typical standard afterward, “It was a tough match, and of course I'm disappointed. But I was not feeling the ball at all tonight. I was not playing good from the first point. It was not my day,” she said. “I missed a lot and I make a lot of unforced errors. So, this was not my game like I play normally.”

Next up for Vandeweghe is a date with French Open champion Garbine Muguruza who defeated Sorana Cirstea in straight sets on Sunday.