Serena Williams has dedicated her emotional seventh Australian Open triumph to vanquished sister Venus after becoming the most successful women's player in professional tennis history.

Williams upstaged Venus 6-4 6-4 on Saturday night to land not only an unprecedented seventh title at Melbourne Park but also an open-era record 23rd grand slam singles crown.

The all-conquering American eclipsed German great Steffi Graf's modern-day mark of 22 grand slam titles and also regained the world No.1 ranking she'd relinquished last September to Angelique Kerber.

"I would really like to take this moment to congratulate Venus. She is an amazing person," Serena said.

Advertisement

"There is no way I would be at 23 without her. There is no way I would be at one without her.

"She is my inspiration, she is the only reason I am standing here today and the only reason that the Williams sisters exist.

"Thank you Venus for inspiring me to be the best player that I could be and inspire me to work hard. Every time you won this week I felt like I got a win too.

"I definitely think she will be standing here next year. I don't like the word 'comeback'. She has never left. She is such a great champion."

Among countless other records, Williams - at 35 years and 125 days - also extended her own record as the oldest woman to win a major in the half-century open era.

Margaret Court fittingly had the best seat in the house, front and centre in the President's Box at Rod Laver Arena, as Williams also drew within one slam of the legendary Australian's record 24 singles majors with a typically ruthless display.

The superstar siblings were clashing for the ninth time in a grand slam final - but first since 2009 - and this was Serena's seventh success in the matches that mattered most.

After breaking Venus's serve in the opening game of the match, Serena banished any suspicions she might go easy on her older sister when she obliterated her racquet after being on the wrong end of a net-cord winner.

The second seed received an automatic code violation for the outburst but swiftly took out her frustrations on Venus with a ferocious forehand return winner the very next point.

But after breaking Venus again, Serena coughed up three double-faults the next game to immediately give up her advantage.

Serena finally held for the first time in the sixth game, broke Venus once more and closed out the opening set with her seventh ace.

With a 20-from-20 record in grand slam finals after taking the first set, Serena could see the finish line.

But eyeing her own watershed win, 36-year-old Venus stayed with her for much of the second set.

Alas, women's tennis's fiercest competitor gained her fourth break at 4-3 before closing out the match after one hour and 22 minutes to deny Venus a long-awaited first Open crown - and eighth career major.

After losing last year's final to Kerber, and then the French Open decider to Garbine Muguruza, Serena now holds two of the four grand slam trophies - Wimbledon and the Daphne Akhurst Memorial Cup for her emphatic victory on Saturday night.

Venus was as gracious in defeat as Serena was in victory.

"Serena Williams, that's my little sister guys. Congratulations Serena on No.23. I have been right there with you, some of them I lost right there against you," she said.

"Yes, that is weird but it is true. But it has been an awesome thing, your win has always been my win, I think that you know that.

"Those time that I couldn't be there, didn't get there, you were there.

"I am enormously proud of you. You mean the world to me."

AS IT HAPPENED
11.02pm

That's it. Serena serves out the game to clinch the championship 6-4 6-4, her 23rd Grand Slam singles crown, an incredible 18 years after winning her first.

10.54pm

Venus holds but Serena now set to serve for the match.

10.51pm

Serena's in full flow now, easily holding serve to move to a 5-3 lead in the second set.

10.46pm

Serena breaks serve at the third attempt in this game - the first break in this set - and now looks likely to push on to claim the title.

10.42pm

The second set continues to go with serve, with the score now 3-3.

10.36pm

A couple of unforced errors prove crucial for Venus as Serena holds serve for 2-2.

10.32pm

What a fightback from Venus. She saves three break points and reels off five consecutive points to hold serve and lead 2-1.

10.26pm

The second set starts with an important hold of serve for Venus.

10.22pm

Serena clinches the first set 6-4 with an ace, overcoming early breaks to finish strongly in a set which lasted 41 minutes.

10.17pm

Serena wins her third consecutive game to take a handy 5-3 lead.

10.00pm

Does anyone want to hold serve? Make that four breaks from four, as Venus comes right back to level proceedings.

9.53pm

Three games, three breaks of serve. Serena gains her advantage back, and now will try and consolidate it with a strong serving game. 2-1.

9.45pm

The final is underway, and Serena has immediately broken serve to take a 1-0 lead. But, breaks of serve are less important in women's tennis than on the men's side, and Venus immediately breaks back. A lively start.