Andy Murray identified winning a topsy-turvy opener as the key to his straight-sets victory over American Sam Querrey in the fourth round of Wimbledon.
The fourth seed broke early in the match and seemed poised to take the set easily when he served for it at 5-3.
But Querrey, whose 6ft 6in frame makes him a serving threat, broke back and then had points to win a third consecutive game only for Murray to dig deep and then break again.
Explaining that sudden dip, after sealing a 7-5 6-3 6-4 win, the 23-year-old said: “It happens sometimes. You can play bad games. I'm not going to play my best for every minute of the tournament.
“You have to deal with the situations when they arise. I did a good job of getting that set. Mentally for him it could have been quite difficult after having the chances and getting back into that set. So to not take it would have been tough for him.”
There has been no sign of the frustration Murray has often displayed on the court when things have not gone his way, and he feels accepting those fluctuations in form will be key to his progress.
“Some days things aren't going to be going well,” he explained. “You just have to learn how to deal with it.
“Today I did a lot more running than I did in my first few matches, but I had to. Sometimes you have to accept that.
“On other days you can be dictating a lot of the match. You need to be prepared to change your tactics or change the way you're playing when you're out there if you want to win the big tournaments.”
After the first-set wobble Murray had things largely his own way against an opponent who struggled to balance aggression with consistency.
He broke Querrey in the fourth game of the second set and this time there were no alarms as the 23-year-old served it out. The third set was tight, with both men holding serve reasonably comfortably until the Scot put together a series of superb points at 4-4.
Pick-ups and passing shots were vintage Murray and the crowd were in raptures when he clinched the crucial point with a forehand winner.
Querrey made his best effort to break back but one overcooked forehand too many sealed his fate.
The Scot goes forward to a quarter-final meeting with Jo-Wilfried Tsonga as the only man not to have lost a set.
One worry for Murray was his first-serve percentage, which was down at 45% for the match compared to around 60% in his previous three contests.
“It was different to the first few matches,” he said.
“I served great in the first three matches and I didn't serve so well today.
“But I was good from the back of the court and I didn't make as many mistakes. I had to defend well, and I did.”
Rafael Nadal eased any concerns over his fitness with a dominant victory over Paul-Henri Mathieu.
The Spaniard made it 10 wins from 10 career meetings against Mathieu with a 6-4 6-2 6-2 victory on Court One to set up an eye-catching quarter-final with sixth seed Robin Soderling.
Mathieu now shares with Fernando Verdasco the worst head-to-head record against Nadal, whose recent injury worries were little in evidence during the two-hour encounter.
The Spaniard, who missed the defence of his title last year with tendinitis, said he was “scared” about a flare up of one of his knees during his win over Philipp Petzschner in the last round.
World number one Nadal also had to call on the trainer to deal with an arm injury during the five-set encounter, but the seven-time grand slam title winner looked in peak condition, showing good agility and hitting brisk winners off both sides.