Tennis news - Serena Williams hammers Tatjana Maria in 49 minutes

The seven-time champion dispatched of her unseeded German opponent and sent out an ominous signal to her rivals on her first competitive outing since her infamous outburst at the umpire during her US Open final defeat to Naomi Osaka.

Williams was pregnant when she won the last of her 23 Grand Slam titles at Melbourne Park and showed she has lost none of her brutal power and athleticism in the match between the two mothers at Rod Laver Arena.

The American took the first set in just 18 minutes was in business-mode as Maria only succeeded with two first serves in the opener.

By the start of the second set, the world No 73 had only collected five points but those in attendance at the Rod Laver Arena responded warmly as she finally got on the board in the 10th game.

It would merely delay the inevitable, however, as the 37-year-old Williams wrapped up the match following another unforced error from her opponent - and she will face Eugenie Bouchard in the second round.

"I have so many good memories of the last time I was here," said Williams.

"It was literally the best win of my career, so it's just good to get back. I'm glad that I was able to come out and do what I needed to do.

"The last time I was here I was pregnant and playing at the same time, so it's kind of weird walking back on by myself this time."