Andy Murray admits he had to win ugly to reach the US Open last 16 after the British number one battled past Italy's Paolo Lorenzi.
Murray was far from his best in Arthur Ashe Stadium but he dug deep to win 7-6 (7/4) 5-7 6-2 6-3 and book a fourth-round meeting with Bulgaria's Grigor Dimitrov.
The Scot has still only dropped one set so far this year at Flushing Meadows, but he made 63 unforced errors against Lorenzi - three times as many as he committed in either of his opening rounds.
After a poor second set, however, Murray tightened up in the third and fourth, pulling away from the Italian to seal a routine victory.
"It took me a little bit longer than I would have liked to work things out but I won, got through, and I didn't play good so I'm happy with that," Murray said.
"He's ranked 40 in the world. He's pretty good, so I expected a tough match. I expected long rallies.
"I'm just disappointed with the amount of errors I made. I was quite impatient at times. That cost me in the first and second sets.
"When I was more patient and waited for the right balls to go for I played much, much better and dictated more of the points. I wasn't going for too much."
Lorenzi had won only two grand slam matches in his whole career before this tournament, but the 34-year-old claimed his first ATP title in July and had knocked out France's Gilles Simon on Thursday.
"Maybe it's a matter of confidence," Murray said.
"When you win an ATP title at that age, maybe you realise, 'I'm much better than I thought'. Sometimes that can happen as well."
Britain now has three players - Murray, Kyle Edmund and Johanna Konta - in the last 16 of a grand slam for the first time since 1964 when Michael Sangster, Graham Stilwell and Roger Taylor made it through in Australia.