Serena Williams made history at the Australian Open on Saturday as she overcame older sister Venus in the final to claim a record-breaking 23rd grand slam.

Stuck on 22 majors since taking out Wimbledon last year, 35-year-old Serena finally surpassed Steffi Graf for the Open-Era record by winning in straight sets on Rod Laver Arena.

Serena, who lost to Angelique Kerber in the decider 12 months ago at Melbourne Park, held her nerve to see off Venus 6-4 6-4, as she eclipsed Graf with a seventh Australian Open crown.

Margaret Court's overall record of 24 major titles is now within touching distance for Serena, who reclaimed the WTA's top ranking as a result.

At a tournament highlighted by the revival of seasoned champions — Rafael Nadal and Roger Federer are set to contest the men's final on Sunday — there was nostalgia in the air as Serena and 36-year-old Venus locked horns in the final of a grand slam for the first time since Wimbledon in 2009, with this their ninth meeting in a major decider.

Second seed Serena had won six of their previous eight matches in grand slam finals but the pressure of the occasion and the emotion of the opponent was clear to see from the outset.

Having appeared to settle early, breaking in the opening game, Serena then hit three consecutive unforced errors to hand the break straight back to 13th seed Venus, a seven-time grand-slam champion featuring in a major final for the first time since the pair's meeting almost eight years ago.

And Serena, looking tense and tight, struggled after that moment, with emotion and frustration clearly evident on her face and in her play.

While Serena looked below her best, the topsy-turvy start continued into the third game with another break of serve. After receiving a code violating for breaking her racket during a rally, the former world No.1 went on to reclaim the break at the third time of asking as Venus fired a forehand into the net.

Venus tried to keep the points short against her powerful youngster sister, who looked under pressure and frustrated as she dropped serve again, and, after 23 minutes and five games, there was finally a hold of serve as the older sibling briefly gained the upper hand, but the see-sawing battle continued when Serena broke for a 4-3 advantage.

Serena consolidated, having dug herself out of 0-30 hole, and she never looked back, closing out the opener with an ace after earning triple-set point.

Up a set and with an imposing 20-0 record after winning the opener in the final of a major, Serena threatened to run away with the title but Venus composed herself to halt her sister's momentum.

An evenly-matched set continued through five games with no breaks of serve but Venus's body language faded as the set wore on, with more sprayed shots inviting punishment.

Serena eventually pounced by breaking serve in the seventh game, earning a lead she did not relinquish, despite Venus's best efforts, as she emerged the undisputed queen of women's Open era tennis, with one more milestone left to hunt down.

STATISTICAL BREAKDOWN 

Serena Williams [2] bt Venus Williams [13] 6-4 6-4

WINNERS/UNFORCED ERRORS 
Serena – 27/23
Venus – 21/25

ACES  
Serena – 10
Venus – 7

BREAK POINTS WON 
Serena – 4/11
Venus – 2/3

FIRST SERVE PERCENTAGE  
Serena – 61
Venus – 69

PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE  
Serena – 76/46
Venus – 67/29

TOTAL POINTS  
Serena – 69
Venus – 59