Fireworks, strobe lights, thumping music and gyrating dancers on the court of Arthur Ashe Stadium. It can only mean one thing: the official start of the U.S. Open.

John McEnroe and Martina Navratilova, singles champions from three decades ago, slammed tennis balls into the stands before Monday night's matches to ceremonially light the Empire State Building in U.S. Open court blue.

And first-year New York City Mayor Bill de Blasio officially welcomed the 700,000 fans to the two-week tournament, saying ''the U.S. Open is where it's at!''

That was all a prelude to pounding rock tunes from the band Fitz and the Tantrums, accompanied by booming fireworks, flashing strobe lights and a team of dancers gyrating on the court over projected images of the game's biggest stars.

Thinking of Ukraine

For Ukraine's Sergiy Stakhovsky, just keeping his mind on tennis these days is a challenge.

Stakhovsky, who lost a first-round match to Andreas Seppi of Italy 6-3, 6-1, 6-4 on Monday, acknowledged the current political unrest in Eastern Ukraine is a distraction.

''Two weeks ago I was there and not very far from what is happening,'' Stakhovsky said, adding that he preferred not to ''disclose'' exactly where he was. ''It all gets under your skin and it's kind of hard to live without information about what is going on and if there's any updates.''

Despite the instability in his country, Stakhovsky believes there was no reason for the upcoming Davis Cup matches between Ukraine and Belgium, scheduled from Sept. 12-14, to be moved out of Kiev to the neutral venue of Talinn, Estonia.

On Aug. 7, the Davis Cup committee came to a non-unanimous decision that it would be safe for Ukraine-Belgium to go ahead as planned and play in Kiev.

The Belgian Tennis Federation appealed that decision. On Aug. 12, the ITF Board of Directors upheld Belgium's appeal and advised the Ukrainian Tennis Federation to select a neutral site. The winning country will clinch a spot in the main draw of next year's Davis Cup.

''The Ukraine national football team is playing Portugal and Slovakia next week in Ukraine and 80,000 people will be at the stadium and that's no threat to security,'' Stakhovsky said. ''And then we have a Davis Cup tie, in which there'll be a maximum of 5,000 people in a closed venue, and it's a breach of security.''

To make his point that it's absurd for Ukraine to lose its right to home matches that would have been held far away from the strife, Stakhovsky noted the 1,000 miles between recent riots that took place in Ferguson, Missouri, and New York City.

''What -- should we cancel the U.S. Open?'' Stakhovsky said. ''It's the same topic and the same in Kiev.''

Strictly not watching

Andy Murray isn't one for reality TV -- even if his mother is starring on it.

British Fed Cup captain Judy Murray is set to compete this season on the BBC's ''Strictly Come Dancing,'' the show that inspired ''Dancing with the Stars'' in the U.S.

''If it makes her happy, then I will support her. I'm not really into those shows, but she loves it,'' her two-time major champion son said Saturday as he prepared for the U.S. Open.

''I mean, she watches it all of the time, talks about it all the time,'' he added with a grin.

Not that he plans to tune in.

''Probably not, no,'' Murray conceded.

His mother must be an avid dancer, right?

''I don't believe I have ever seen her dance, to be honest,'' Murray said. ''It will be interesting.''

What Murray is a fan of is the NBA, and with an offseason home in Miami, he has Heat season tickets. The Scot didn't appreciate the implication that he might give them up now that LeBron James has left town.

''We don't do that,'' Murray shot back. ''In the U.K., you don't change teams when someone leaves.''

Murray took a day off from practicing Friday for a busy slate of spectator sports. He followed Northern Ireland's Rory McIlroy at The Barclays in New Jersey, then attended the USA Basketball exhibition at Madison Square Garden at night. It was the first time he'd observed professional golf live.

''It's like pretty much any sport,'' Murray said. ''When you watch them up close, it's impressive.''

Beating the spread

Victoria Azarenka's greatest athletic accomplishments: Winning the Australian Open twice. Reaching the No. 1 ranking. Spreading her toes?

Azarenka missed the French Open and most of the spring because of a left foot injury. The runner-up to Serena Williams the last two years at the U.S. Open, she's seeded just 16th this time because of the layoff.

Part of her rehab was seemingly the simplest of physical actions.

''The big thing that I had to learn (was) how to spread my toes,'' she explained Saturday. ''That's not a joke. It's for real. Because, you know, spending so much time in the shoes, some people cannot really spread their toes. I could not do it on my left foot. I had to learn that, and it took me about two weeks, because it was constant, mental thing. It wouldn't move.''

When it finally happened, she recalled with a smile, ''I ran and I screamed in the hallway, like I don't know - I never been so happy in my life.''