Venus Williams

Gauff, already the youngest competitor ever to qualify at the All England Club in the professional era, showed the poise and power of a much older, much more experienced player, pulling off a 6-4 6-4 victory in the first round over Venus Williams, who at 39 was the oldest woman in the field.

When it ended, Gauff dropped her racket and put her hands on her head. After a handshake and exchange of words at the net with Williams, Gauff knelt by her sideline chair and tears welled in her eyes. Up in the stands, her father leaped out of his seat.

Serena won 7-6 7-5 against Kiki Bertens before Venus won 6-3 6-4 against Sorana Cirstea to tee up a third-round clash.

That will be their earliest meeting at a tournament since the first match they ever played - a second-round tie at the 1998 Australian Open.

Serena's first-round win earlier this week was her first victory since a 14-month absence after giving birth. She leads her elder sister 17-11 in all-time meetings.

Elsewhere, US Open finalist Madison Keys was eliminated by wildcard Danielle Collins, the world No 116.

The 20-year-old Swiss played the 37-year-old American great to perfection, soaking up the fifth seed's firepower and attacking her wavering serve with abandon.

In a tense grand slam opener that felt more like a final, Williams battled to keep touch in an enthralling second set, but Bencic unleashed two blazing forehand winners to close out the match in the 12th game.

The resurgent Bencic will meet the winner of Johanna Larsson and Luksika Kumkhum in the next round.

Jerome Barson, 78, was fatally injured when the vehicle in which he was a passenger crashed into the side of Williams' car in Palm Beach, Florida in June.

Barson's wife Linda, who was driving at the time of the collision, suffered a broken arm and other injuries while 38-year-old Williams was unhurt.

Victory for the Dane, who lost in the 2010 WTA final and twice in the US Open final, ends years of near misses on the biggest stage and caps a memorable 2017, where she reached eight finals and added a second title to the Pan Pacific crown which she won in September.

While Wozniacki put an end to her season of falling agonisingly short, it was another high profile runners-up finish for Williams, who had become the oldest woman to reach the final in the tournament's history, after beating Caroline Garcia in Saturday's semi-final.

Wozniacki has enjoyed a fine season having reached seven finals but she has the chance to claim the biggest title of her career after a 7-6 6-3 victory over Karolina Pliskova on Saturday in the opening semi-final.

The Dane lost in the final of this even in Doha in 2010 and has also suffered defeat in two US Open finals but she continued her week in Singapore with a dominant display to end Pliskova's season and year-end no 1 dream.

The American world No 5 advanced to her fifth semi-final at the season finale after a determined 7-5 6-4 victory in one hour and 41 minutes.

Wiliams' win, which acts as some form of revenge for her Wimbledon final defeat to Muguruza, sees her finish second in the White Group behind Karolina Pliskova and the seven-time Grand Slam champion will next meet either Caroline Wozniacki or Caroline Garcia.

The match, lasting 3 hours, 13 minutes, featured 20 service breaks, with neither player finding much confidence on their service games.

The 37-year-old Williams dropped her serve nine times, while the 20-year-old French Open champion conceded serve 11 times.

"I don't know if there was any luck for me tonight, I just had to work for every point,'' the fifth-seeded Williams said. "It's not easy to lose the first match, and both of us were in the same situation. What else can you do but fight to live another day?''

Barty has enjoyed a breakthrough year in 2017, claiming her first WTA Tour title and climbing into the world's top 50 for the first time.

However, prior to Wednesday, the Australian had lost all six of the matches she had played against top-10 opponents.

That winless streak was broken in Cincinnati as Barty overcame a second-set wobble to beat Williams 6-3 2-6 6-2.

"To play Venus on such a big stage is a privilege for me and to play as well as I did, I'm really excited," said Barty.

After some tense early exchanges, the Spaniard cut loose, winning nine straight games to claim a second grand slam title to add to last year's French Open.

The 23-year-old fell to the floor in celebration after clinching victory in an hour and 17 minutes. It was her second Wimbledon final, having lost to Venus' sister Serena on the same stage in 2015.

"Two years ago I lost in the final to Serena and she told me one day I was going to maybe win and hey, two years after here I am," she said in a courtside interview.