That was the advice to Nick Kyrgios from coaches and mentors as the brash teenager from Canberra smashed 26 aces and 68 winners in a four-set demolition of world No. 23 Mikhail Youzhny at the US Open, but almost blew it all by blowing his lid.

Kyrgios, 19, was handed three code violations during the first-round win - one shy of being disqualified. He smashed a ball out of the stadium in frustration - similar to what he did at Wimbledon - then dropped the F-bomb before being docked a game in the fourth set for a second audible obscenity.

It was the kind of performance that even had "Superbrat" John McEnroe implying "you can't be serious?" "Most players never even see that [game] penalty. I've seen it," he said during his commentary of the match.

When he kept his temper in check, Kyrgios disposed of Youzhny 7-5, 7-6(7-4), 2-6, 7-6 (7-1). He now faces another tough assignment against Italian Andreas Seppi, who has a world ranking of No. 49 - 11 spots higher than Kyrgios.

The pressure of expectation is building on Kyrgios, the former junior world champion, following his quarter-final finish at Wimbledon, which included a stunning upset of world No. 1 Rafael Nadal.

Kyrgios said he had been caught up in "the heat of the moment" against Youzhny. "I was frustrated the way I was playing ... it was just an outburst and hopefully I will be able to control that the next time I play.

"I'm probably expecting a lot out of myself at these sort of tournaments. I have to know I'm still young and it's a long journey. I have to just be patient.

"It just comes from having high expectations most of the time. I have been an emotional player most of my career. Maybe I will be able to manage it in the future. It's a work in progress."

Kyrgios' coaches, Josh Eagle and Todd Larkham, have been trying to manage Kyrgios' on-court temperament. Larkham, who coached Kyrgios as a junior, said he had always walked a fine line.

"He likes to get pumped and fired-up to play well, but he's just got to channel it," Larkham said. "It's got to be more positive than it was [on Monday]. He doesn't play that well when he's that angry.

"We're certainly advising him to try and control his emotions better. There's a lot of fire there, a lot of passion, he wants to be a great player. Sometimes he wants to win too badly and it boils over. He's going through a learning curve, how to deal with all that pressure and expectation."

Larkham said there was no need to intervene yet.

"An occasional warning is fine, but gee, he pushed it to the limit this match," he said. "Josh has gone through it with him, Nick was very apologetic after the match. Hopefully next round he would have learnt from those mistakes.

"Pat Rafter's there passing on all his experience in grand slams, so he's got good people advising him. He'll realise at some stage what he needs to do to win and that if he gets too angry it's not going to help him."

Former Australian tennis star Wally Masur said it was understandable Kyrgios was feeling a weight of expectation going into the US Open - the first major he has qualified for on rankings alone.

He suspected Kyrgios would settle into the tournament, but warned he needed to keep his cool against the better players.

"He's not the young Nick Kyrgios that entered into Wimbledon as the big underdog with all the potential in the world. He's actually now established himself as a bona fide player," Masur said.

"It's just a reaction to pressure. When he's calm, he'll play his best tennis. You saw that against Nadal. He can still be an extrovert, pump his fists, that's who he is. But [outbursts] can show your opponent a weakness. It's a bit like playing poker, the best players in the world are pretty good poker players in the sense that it's hard to read them.

"Having that match under his belt, I actually think he'll breathe a sigh of relief and settle in now."