Serena Williams battles through errors to beat Kiki Bertens at US Open

Serena Williams

If this were a fight, it might have been called off before a blow had been landed. But Kiki Bertens, a smiling, 23-year-old Dutch qualifier who looked pleased just to be here, made a decent fist of her impossible assignment in dappled light on Arthur Ashe and pushed Serena Williams at least to the lower slopes of anxiety on day three of the 2015 US Open.

Related: Andy Murray predicts better tennis under Arthur Ashe roof at US Open | Kevin Mitchell

Williams took an hour and a half to win 7-6, 6-3, recovering from 1-3 in the first set and 0-4 in the tie-break. She served well enough – 10 aces and 20 unreturned among the 164 points contested – but 34 unforced errors, to 31 by her opponent, told a story of struggle under pressure.

The American – who had the luxury of a farcical retirement win for the loss of only five points against the injured Russian Vitalia Diatchenko on Monday night – will want better stats than those when she plays her compatriot Bethanie Mattek-Sands in the third round.

Williams at times did not move well, laterally, and a stronger, more reliable hitter than Bertens could have had her in deep trouble but she responded with class when it was needed.

Mattek-Sands, whose court presence and hunger for the spotlight in a variety of flash outfits often outstrips her results, played well to beat another American not shy of publicity, Coco Vandeweghe, 6-2, 6-1 on Louis Armstrong.

Beyond Mattek-Sands for Williams – and it is reasonable to look that far ahead – lies either another American in Madison Keys, who beat the 20-year-old Czech Tereza Smitkova for the loss of only three games, or her first seed in this tournament, Agnieszka Radwanska. The former world No2 was way too good for her fellow Pole Magda Linette, who had beaten her sister, Urszula, in the opening round.

None of these players should significantly delay Williams on her path to the first calendar grand slam since Steffi Graf’s in 1988 – but there is no sense of triumphalism in the champion’s camp – far from it. She protests to the satisfaction only of sycophants and fools that this is “just another title” – as in just another title to add to the 69 that have gone before, 21 of those majors, with the added value of being her fourth of the year, the fabled grand slam. But she is nervous and what she is doing is dampening speculation to make the task less stressful. It is a trick of the mind.

Her nerves surfaced early on Wednesday afternoon when Bertens, ranked 110 in the world and with little more ambition here than avoiding embarrassment, came within three points of taking a set off the best player in the game, certainly since Graf, and possibly reaching further back to Margaret Court and other legends from the distant past.

Yet it was a mismatch on paper but not on court. Williams made hard work of it, encouragement, no doubt, to her rivals, and a slight worry to herself and her coach, Patrick Mouratoglou, who has had such a blessed association with the world No1 since she tumbled out of the French Open in 2012, winning eight of the 13 major championship titles in which they have been a team, on and off court.

Williams has earned nine times more this year – $9,792,645 – than Bertens has earned in her career, albeit a much shorter one. (It is a bit of a mind-boggle to remember Williams won the first of her slams here in the last century). The defending champion’s 80 career wins at this venue are 40 times more than Bertens has managed. This was Williams’ 50th win of the season in 53 matches, Bertens’s 14th defeat in 24.

Williams says she pays no heed to numbers. She is paying very close attention indeed to these ones, as they click up every couple of days, easing her towards what most expect to be a memorable final weekend. So far, despite a couple of minor bumps, the path has been smooth.

Powered by Guardian.co.ukThis article was written by Kevin Mitchell at Flushing Meadows, for The Guardian on Wednesday 2nd September 2015 23.50 Europe/London

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