Venus Williams stands in the way of Serena Slam

Serena Williams’ historic pursuit of the calendar grand slam was transformed into an emotionally supercharged family affair the world No1 could certainly have done without on Sunday.

With almost perfect symmetry, the most garlanded tennis sisters in history won back-to-back matches here to set up a quarter-final encounter between themselves on Tuesday.

It will be the first time they have met at this stage in New York since 2008 – their 14th meeting in majors overall – and will, without doubt, be one of their most poignant battles as the younger Williams sister attempts to complete her clean sweep of 2015.

No sooner had the dust settled on Venus' 6-2, 6-1 triumph over the Estonian qualifier Anett Kontaveit than Serena strode out on to the Arthur Ashe court and promptly extinguished the youthful exuberance of Madison Keys 6-3, 6-3.

“It was important to get a great start. That was my only chance,” said Serena, who looked visibly uncomfortable when contemplating the encounter with her older sister.

“I became more relaxed and everything worked well. I don’t feel any pressure. Venus is playing great, I barely had a chance to get ready because she was playing so fast. At least one Williams will be in the semis.”

Keys, who hits her groundstrokes harder than anyone on the WTA tour, had hoped to overpower the world no1 who had shown glimpses of fallibility in the last two matches, twice dropping the first set before predictably responding with her intoxicating blend of force and aggression allied with supreme shot selection.

The 20 year-old, coached by former US Open champion Lindsay Davenport, certainly struck the ball with fierce intensity from the onset .Though when the lively world number 19's serve finally failed allowing Williams to break for 5-3, the writing appeared to be on the wall.

Seven unforced errors and a second-serve points percentage of only 36% were the numbers which undid Keys here in the first set. A double fault sealed the match after 68 minutes in what was Williams’ most complete performance so far.

The 33-year-old’s six unforced errors, compared with the 19 which came from the other end of the court, illustrated the levels of concentration on display.

“It’s been awesome to have such a great sibling rivalry with Serena. We are proud of each other. We inspire each other,” said Venus, whose resurgence in 2015 is shown in her reaching the quarter-finals both here and in Australia, putting to an end a period in which her last appearance at this stage stretched all the way back to 2010.

The senior Williams sister, 35, who is making a record 17th appearance here at the final major of the year, was rarely perturbed by the Estonian qualifier who had eliminated Briton Naomi Broady on her way into the fourth round.

It took the American a mere 24 minutes to wrap up the first set amid typically humid and stifling conditions on the Arthur Ashe court. Kontaveit, perhaps understandably at the age of 19, appeared overawed by the task at hand when taking on the oldest, and most experienced, campaigner still in the draw.

Two quick breaks in the second had Williams firmly in control, her vice like grip from the back of the court refusing to allow the Estonian even a mere glimmer of hope.

Ultimately, the seventh game of her debut foray at this tournament was one too far and Kontaveit headed out of the tournament to be joined by the luckless Canadian Eugenie Bouchard who was forced to withdraw before her round of 16 encounter with Roberta Vinci after sustaining a head injury following a fall in the shower on Friday night. Venus said: "I don't think anyone wants to be a spoiler. I think people love to see history being made. I think. No one is out to be a spoiler, but at the same time, you're focused on winning your match even though the circumstances are really much different than you.

“What’s the one thing about her which gets under my skin? Well, we have a family gathering every year, and every year I don’t get much say. She always picks the theme, and so that bothers me.”

(Guardian service)