Johanna Konta shrugged off her second-round health scare at the US Open with a straight-sets victory over Switzerland’s Belinda Bencic to move into the last 16.
Konta had suffered an on-court collapse only 48 hours earlier at Flushing Meadows, but she showed no signs of weakness as she strolled past Bencic 6-2 6-1.
The British No 1 will next face Anastasija Sevastova, the Latvian who knocked out third seed Garbine Muguruza in round two.
“I feel overwhelmingly happy,” Konta said.
“I felt I did a good job playing the match at hand and I focused all my energies into this match here. I was happy how I dealt with things.”
Bencic is undeniably talented and, at 19, the second youngest player ranked inside the top 30, but the Swiss simply never competed in what was a demolition on the new Grandstand court.
Konta did not give away a single break point, she won 19 out of 20 on her first serve and unleashed a hefty 29 winners to her opponent’s nine.
After losing two of the opening three games, the Briton won 11 out of the next 12 en route to victory in a brisk 52 minutes.
Konta’s near-perfect performance was all the more impressive given it came two days after her traumatic bout of illness in the second round when, curtailed by heat and fatigue, she collapsed on the baseline and needed almost 15 minutes of treatment to continue.
As the second match on this time, Konta was back playing in the heat of the day, but both the temperature and humidity were less fierce and she offered no signs of residual discomfort.
Instead, Konta is emerging from a tricky section of the draw as a major force and she will certainly start as favourite against Sevastova, who has climbed to 48th in the rankings following a temporary retirement in 2013.
If she comes through, America’s Madison Keys or the resurgent Caroline Wozniacki may stand in the way of her reaching a second grand slam semi-final this year.
Konta, however, insists on staying in the present and she can take great heart from a ruthless display, which took hold in the fourth game when she first broke Bencic’s serve.
It came after a clipped forehand pass and then a booming return into her opponent’s feet as Bencic struggled to keep pace with the blistering power she was up against.
The onslaught was just beginning as Konta won seven games in a row to take the first set and a 2-0 lead in the second, prompting Bencic to drop her racket to the ground, less in anger than sheer bewilderment.
Bencic was certainly well below-par, this tournament coming after a year disrupted by illness and injury, but there was little she could do as Konta never let up.
Another hammering return sealed the double break for 5-1, before a winning Konta forehand finally put Bencic out of her misery.
Novak Djokovic has played only six games for two victories at the US Open after Mikhail Youzhny retired from their third-round match with a leg injury.
Djokovic was also handed a walkover in round two on Wednesday, when Jiri Vesely pulled out before a ball was hit – and the Serb only had to lead 4-2 before Youzhny followed suit.
The withdrawals have come as a timely boost for Djokovic, who has been struggling with both wrist and arm injuries at Flushing Meadows.
The world No 1 last came through a full match on Monday and he will have enjoyed almost five days rest before facing either Beverley’s Kyle Edmund or American John Isner – who were in action late last night – in the last 16.
“I don’t think I ever had this situation in my career,” Djokovic said.
“Obviously I wish Mikhail a speedy recovery. I think he carried the injury into this match, that’s what he said.
“I’ll try to get the positives out of these six games. I did start with good intensity so I’ll try to carry this into the next round.”