Serena Williams defeats Ashleigh Barty 6-2 6-1
Novak Djokovic beats Lukas Lacko 6-3 7-6 (7-2) 6-1
Laura Robson & Heather Watson knocked out
Andy Murray plays Go Soeda on Tuesday
It's time to call it a day on today's live text commentary. Thanks for joining us. There will be more tennis on Tuesday when Andy Murray, Rafael Nadal and Victoria Azarenka come to the party so join us for live text commentary on Murray's opener against Japan's Go Soeda, which won't get under way before 0600 GMT, if that's any use at all for those of you who will be setting your alarms at such an unwelcome hour.
Judy Murray
Great Britain Fed Cup captain on BBC Radio 5 live sports extra
"Serena looks focused, determined, on the top of her game, and in great physical shape. If she's a little bit off her game then perhaps one of the other big hitters, like Sharapova, have a chance, but in this form and fully healthy she's a very tough person to get past."
Williams's next opponent will be Serbian Vesna Dolonc who earlier beat Spain's Lara Arruabarrena 2-6 6-2 6-4. The 32-year-old will be favourite for that one, as she will be in every match she plays in Melbourne Park this year.
Williams joins the crowd in applauding Barty from the court. "I was so ready today because she's such a good player with such a good future," says the world number one. "I would love to have a win here but there are so many tough opponents in the tournament so I have to come out and enjoy myself."
Time running out for Barty as a wild forehand presents Williams with match point at 30-40. Williams, though, has yet find her killer instinct and allows her opponent off the hook. The world number one watches a Barty forehand go long for a second match point and the Australian wilts on the next point, directing a forehand into the tape.
Judy Murray
Great Britain Fed Cup captain on BBC Radio 5 live sports extra
"Serena is playing with much more intensity over the last year. You can see it and hear it because she really berates herself when she loses a point. She wants to play perfect tennis and very nearly does. She has this incredible serve, she's moving so well and it's difficult for the other girls to know what to do against her because she is so relentless."
The Williams serve working like clockwork. The dogged Barty attempts to pass Williams, who cuts an intimidating figure at the net, but it takes some doing to get the better of the top seed and the American volleys home for a 30-0 lead. An ace - her sixth of the match - eases Williams to 40-15 and another boomer takes her to within a game of wrapping up the match. Fuss free stuff.
A tame Williams backhand plonks into the net and the crowd celebrate as if Barty has nicked the set in a tie-break. The teenager is some way off winning this set, of course, although that opening point boosts her confidence and she goes on to hold to 15, smiling wryly as she strides towards her chair for the changeover.
Williams using her experience to see off her opponent by exerting as little energy as possible. Only Lindsay Davenport has played more matches in Melbourne in the Open Era. Barty being forced into needless errors, a forehand bounces long to give Williams a 40-0 lead and a cool ace ends the game. Williams has yet to drop a point on her own serve in this set.
Image source, APMore delicate drop shots have been played on Rod Laver, but Williams will care little about the presentation because it helps her gather three break points. Barty, brave and bold, drags Williams to the net with a drop shot but the subsequent overhead drifts over the baseline and unfortunately the Australian gains no reward for her bravery.
Williams breaks the on-court silence with a high-pitched scream as she wallops an overhead from Barty's grasp. Another hold to love and the top seed consolidates her advantage.
Williams collects three break points with little fuss. But the American then nets, which allows Barty to save one break point. A fabulous forehand winner saves another but what has Barty left in her locker? Enough to go toe-to-toe with Williams from the baseline but her resistance is made of tissue paper.
Judy Murray
Great Britain Fed Cup captain on BBC Radio 5 live sports extra
"Ash, when she has served her first serve well, has been able to cause some trouble, but at other times she's facing a barrage from the other side of the court. There are so many points where she can't get into the rally because the ball comes back so fast. She won't be used to this firepower coming at her. It's a world away from what she's used to."
Even though the Australian has her back to the wall, one or two fans attempt to encourage Barty with a few maverick shouts. It's a mixed game from Williams, an ace, then a double fault, before two quick-fire aces help secure her the set. Barty shows a glimpse of her potential with a fabulous crosscourt winner to save one set point, but it takes more than the occasional moment of magic to overcome a woman like Williams.
A double fault from Barty gifts Williams a break point and the spectators in the jam-packed Rod Laver Arena look on in silence. The teenager opts for a drop shot from the back of the court and fails to negotiate the barrier, allowing Williams to close in on the first set.
Image source, Getty ImagesWilliams grunts as she stretches every sinew to put away an overhead, but the top seed is, on the whole, rather quiet, which perhaps indicates she is comfortable and untroubled. The 17-time Grand Slam champion holds to 15 with a forehand winner down the line. Easy peasy.
Oooooooof! 'Take that', says a grimacing Williams as she pounces on a timid second serve to unleash an unstoppable backhand crosscourt winner for 30-30. Barty hanging on, nudging ahead, but a Williams backhand down the line takes the game to deuce. Yet, the 17-year-old comes through a testing period and is awarded top marks for guts.
If you've come in search of an upset them I'm afraid there's nothing to see here. Williams is unfazed by the partisan crowd, though her ruthless serving has given the Aussie faithful little to shout about. But Barty fights back from 40-0 down to 40-30, with double fault ruining the world number one's copybook. Even then, though, there seems little danger of Williams folding, and she doesn't - coming through to extend the gap further.
This is just the second time in her career that Barty, the world number 155, has faced a player ranked inside the top 10. She lost to Petra Kvitova at the 2012 French Open and will probably lose today as Williams collects two break points with ease, punishing the Australian's second serve. The American makes the most of her opportunity, sprinting towards the net to delicately place a volley beyond her opponent.
Image source, APWilliams, whose outfit today is a pink and black dress, is serving with her usual aplomb, racing to 40-0 and ending the match with an irretrievable crosscourt volley by the net.