Australian Open day eight in Melbourne

United States' Serena Williams prepares to serve to Barbora Strycova of the Czech Republic during their fourth round match at the Australian Open. Photo / AP.

The race for the 2017 Australian Open in both the men's and women's draws is now wide open. World No. 1 Andy Murray is no longer in contention after Mischa Zverev upset him on Sunday, so he joins No. 2 seed Novak Djokovic as a mere spectator at the year's first major.

That's good news for the likes of Rafael Nadal and Milos Raonic, who both play today. Nadal takes on No. 6 seed Gael Monfils on centre court tonight and Milos Raonic - still searching for his maiden grand slam trophy - plays Spain's Roberto Bautista Agut.

The man responsible for toppling Djokovic - Denis Istomin - has the chance to add another big scalp to his resume when he plays No. 15 seed Grigor Dimitrov. Young gun Dominic Thiem can improve his burgeoning reputation if he beats Belgian David Goffin.

A seventh Australian Open title is still on offer for Serena Williams, who can get even closer to the silverware with a win over Barbora Strycova. Fresh from her demolition job on former world No. 1 Caroline Wozniacki, Johanna Konta - who enjoyed a watershed moment at Melbourne Park last year during her run to the semi-finals - can give herself a chance to repeat that 2016 effort when she plays Ekaterina Makarova from Russia.

Crowd favourite and the last remaining Australian in the singles draw Daria Gavrilova will endear herself even further to fans in her adopted country if she musters a win against Karolina Pliskova.

SCHEDULE
ROD LAVER ARENA
(2) Serena Williams (USA) vs (16) Barbora Strycova (CZE)
(8) Dominic Thiem (AUT) vs (11) David Goffin (BEL)
7pm - (5) Karolina Pliskova (CZE) vs (22) Daria Gavrilova (AUS)
(9) Rafael Nadal (ESP) vs (6) Gael Monfils (FRA)
MARGARET COURT ARENA
(9) Johanna Konta (GBR) vs (30) Ekaterina Makarova (RUS)
Jennifer Brady (USA) vs Mirjana Lucic-Baroni (CRO)
(15) Grigor Dimitrov vs Denis Istomin (UZB)
HISENSE ARENA
(3) Milos Raonic (CAN) vs (13) Roberto Bautista Agut (ESP)

Serena finally opens up on engagement

Serena Williams has won through to the quarter-finals but still people are interested in her personal life as well as her tennis.

She recently became engaged to Reddit co-founder Alexis Ohanian, and he was a hot topic of conversation in her post-match press conference following a 7-5 6-4 victory over Barbora Strycova.

Here's the transcript of her answers below.

Q: When it came out, the news about your engagement, we were all talking about the fact that you met him in Rome, but it wasn't clear if it was just those days or you had met him in Rome one year ago or six months ago or whenever.

SERENA WILLIAMS: I hope it was a couple of years ago (smiling). No, it was a couple years ago. So no, it wasn't six months ago.

Q: So it wasn't recent?

SW: No, it wasn't recent.

Q: So you were not back in Rome without being there for a tournament? That is what I wanted to know.

SW: Oh, actually, I was, incidentally. I love Rome. You know I love Italy. It's my favourite place.

Q: When you first met, was it just like happenstance or was it at the same party?

SW: Literally by chance. It was just - I was sitting down, and he sat next to me.

Q: Nobody introduced you? You were just at a restaurant?

SW: Yeah, that doesn't happen anymore, right?

Q: Only in the movies.

SW: Right? I live in a movie and in a fairytale in my mind, so I guess eventually it was bound to happen.

Strycova doesn't follow Federer's lead

Barbora Strycova is one of few women on tour who can say they got the better of Serena Williams on the American's serve.

In her 5-7 4-6 loss to the 35-year-old, Strycova's impressive return game worried Williams and kept her in the match.

Earlier in the tournament Roger Federer said he doesn't really practice his returns of serve, but Strycova said that was one of the most important parts of her game, and she puts a lot of time into it.

"Yes, I do (spend a lot of time practising my returns) with my coach," Strycova said in her post-match press conference. "A lot, actually, because I can also change the pace. I can stay back, I can go forward, I can change it.

"So we are working on that and practising a lot.

"It's very important, because women, we are not having such a strong serve, as Serena does. Return is very different for our game (compared to the men).

"Return is important as well as serve."

Williams marches on

Serena Williams was far from her best, but perhaps that's what makes her win against Barbora Strycova even more impressive.

She overcame the Czech 7-5 6-4 on Rod Laver Arena to march through to the quarter-finals and stay in the running to win her 23rd career grand slam.

Williams' serving was off for the most part of the hour and 45 minutes she spent on court - getting her first serve in only 45 per cent of the time - but still she had enough weapons with her ground strokes to win the match, hitting 28 winners to nine.

"It's good to know that I have a plan B or option two," Williams said afterwards when asked about her serving performance. "I was't serving my greatest today ... it's always good to have something to improve on and I know I can do better.

"I love pressure, I feel I play well under pressure."

The No. 2 seed will play either Johanna Konta or Ekaterina Makarova in the quarters.

'Maybe the most horrible of all time'

Williams' serving improved in the first step, but her numbers were still far less impressive than what we're used to seeing from the six-time Australian Open winner. Her first serve percentage stood at 55 per cent, and she was only winning 50 per cent of points when her first serve went in when the score stood at 5-5.

Serving at 5-6, Strycova upped her tally of break points saved to seven, recovering from 0-40 down to force the game to deuce a couple of times. But in the luckiest fashion imaginable, Williams jagged a winner to claim the first set in 55 minutes.

Strycova sliced a desperate forehand that skidded off the baseline, and Williams mistimed her backhand horribly into the top of the net, but it lobbed over like an unintended drop shot. Strycova couldn't get to it in time and the set was over.

There was no celebration from Williams who appeared almost apologetic. Strycova couldn't believe her bad luck, turning to the back of the court and muttering to herself.

How’s this for a set point? #ausopen pic.twitter.com/EVSlyfVMjP

— The Tennis Island (@thetennisisland) January 23, 2017

Serena's serving shocker

It's an uncharacteristically sluggish Serena Williams we're seeing in the early stages of her clash against Barbora Strycova.

Williams served first but was broken, before breaking back herself to level the score up at 2-2. She was struggling on serve to begin with, getting just 33 per cent of first serves in and winning only one point in two service games.

Strycova wasn't much better, getting only 63 per cent of her first serves in play, but failing to capitalise when she did, again winning only one point on serve in her first two games.

"They're really poor service numbers. Serena's at a woeful 33 per cent of first serves in and has only won one point on serve. That's unheard of," Channel Seven's Rennae Stubbs said.

"Strycova - she's only won one point on serve as well ... not the greatest start for either woman."

However, while Williams' serving may have been off, she started to find her groove with the rest of her game as the first set went on. The 35-year-old was hitting harder than Strycova, forcing her behind the baseline, and stepping into the ball with more authority.

Her Czech opponent defended well though and kept herself in points longer than most would be able to against the 22-time grand slam champion.

Strycova saved three set points in a marathon 10th game, eventually holding serve to lock it up at 5-5.

'It changes the course of tennis'

Mischa Zverev has given players around the world the blueprint for success against Andy Murray.

Zverev beat the world No. 1 at Melbourne Park on Sunday 7-5 5-7 6-2 6-4 by defying tennis logic and going back to an old-school approach rarely seen in the modern game.

He spent much more time at the net than most players ever do - and it's a tactic that obviously worked against baseliner Murray.

The Scot played 145 points from the back of the court, but Zverev played just 71. Murray won 42 per cent of his points from the baseline and Zverev won 48 per cent, and it was at the net where his domination shone through.

The German served and volleyed 119 times in the match, winning 59 per cent of those points.

Strategy analyst for the Australian Open Craig O'Shannessy addressed Zverev's unique tactics - unfashionable in this day and age where power hitting from the back is most players' preference - and said his approach was eye opening for both players and coaches across the globe, calling the contest "one of the most important matches our sport has witnessed in a long, long time".

"Zverev took traditional tennis wisdom by the scruff of the neck and shook it senseless," O'Shannessy wrote. "This victory changes the course of our game, making the front of the court relevant once again.

"Tomorrow in Shanghai and St. Petersburg and San Francisco, coaches and players and fans of our great game will once again believe in the front of the court as a viable option.

"Serve and volley is back. Approach and volley is back. If anyone disagrees with you, simply tell them to watch a replay of this match. It will send chills up their spine."