(CNN) -- Andy Murray is focused on winning his first grand slam title, but the Olympic tennis champion is facing new distractions following his success at London 2012.
"Yeah, it's been a bit weird, with people hanging out in front of my hotel room, taking pictures," the world No. 4 said after becoming the first player to reach the third round of the men's draw at the 2012 U.S. Open.
"Some ask strange questions: What did I think of Prince Harry's hotel photos? What do I think about the Crown Jewels?"
"I said, no comment. It's a little different than what I'm used to, but it's fun."
Murray, seeded third in the absence of the injured Rafael Nadal, defeated Croatia's Ivan Dodig on Wednesday for his second successive straight-sets victory in New York this week.
The Scot will next face either 30th seed Feliciano Lopez or his fellow Spaniard Pablo Andujar.
"It was better than the first round, that's for sure. I moved better than I did in the first match and served better, and I was able to dictate more of the points because of that. I was much happier with the way I played," said Murray who lost in the 2008 final at Flushing Meadows.
Spanish fourth seed David Ferrer won his opening match in three sets, beating big-serving world No. 34 Kevin Anderson of South Africa.
Ferrer, who reached the semifinals in 2007, faces into a second round meeting with 78th-ranked Dutch debutant Igor Sijsling.
"It was not an easy match with Anderson," Ferrer said. "He's a really good player. He has very strong first and second serve. I'm happy, because I played well in my first round."
American ninth seed John Isner won a tough first-round encounter with experienced Belgian Xavier Malisse, winning 6-3 7-6 5-7 7-6 in just under three hours as the fourth-set tie-break went to 13-11.
"I wish I could make it easier on myself but I tend to not do that, as a lot of people know," said Isner, a quarterfinalist last year.
He will next face another seasoned campaigner in Finland's Jarkko Nieminen, who also reached the last eight back in 2005.
Seventh seed Juan Martin del Potro booked a second-round clash with young American Ryan Harrison after defeating France's Florent Serra.
The Argentine, U.S. Open champion in 2009, battled to a 6-4 7-6 (7-4) 6-4 victory in two and a half hours against his 116th-ranked opponent, who has never got past the second round in New York
The 20-year-old Harrison, who lost his first-round match last year, matched his 2010 debut achievement by beating Germany's Benjamin Becker in straight sets.
Serbian eighth seed Janko Tipsarevic became the seventh man at this year's tournament to win after dropping the first two sets, having faced a shock defeat at the hands of world No. 129 Guillaume Rufin.
Tipsarevic, whose quarterfinal achievement last year was his best result at a grand slam, finally triumphed in three hours 37 minutes against the 22-year-old Frenchman.
He will next face American Brian Baker, who continued his fairytale comeback by winning his first match at the tournament since his last appearance seven years ago.
The former second-ranked junior player had multiple surgeries which wrecked his career, and had been coaching tennis at Belmont University when he decided to return to the professional tour this year.
Baker, who made it to the second round at the French Open and the last 16 at Wimbledon, beat Czech Jan Hajek in straight sets in the opening match of his home slam.
"I had some nerves. I don't think it was probably the prettiest match ever. A win is a win," said the 27-year-old, now ranked 70th despite still studying for a business degree and continuing his coaching role at Belmont.
"I think just getting out and not having played the U.S. Open in seven years and having expectations and having a lot of friends and family just gives you ... I mean, it's good nerves.
"I think it helps you focus a little bit more and want it a little bit more, but it was exciting time to be back after so much time off."
Veteran German 21st seed Tommy Haas, a three-time quarterfinalist, lost to Latvia's Ernest Gulbis, while Russian No. 28 Mikhail Youzhny also blew a two-set lead as he was beaten by Luxembourg's Gilles Muller.
Muller, who reached the last 16 in 2011, earned a clash with Australia's former world No. 1 Lleyton Hewitt, who is expected to retire after the tournament.
Hewitt, the 2001 champion and a three-time semifinalist, beat young German Tobias Kamke 4-6 6-2 6-1 6-4.