Dimitrov ousted Brian Dabul, a semifinalist in Newport last year, 6-2, 6-4, and Bogomolov rallied against Mischa Zverev, 4-6, 6-3, 6-1. Sixth-seeded Olivier Rochus, a finalist on Newport’s grass courts last year, also advanced, beating Greg Jones, 6-4, 3-6, 6-3.

Top-seeded John Isner is scheduled to play today.

Dimitrov, 20, ranked No. 60 entering the week, is the second-youngest player in the top 100 on the ATP Tour.

“The beginning was real soft, then I thought I’ve got to improvise,’’ he said. “I decided to mix up the game.’’

Bogomolov enters the week ranked 66th and Rochus is 74th.

Rochus also was a semifinalist in Newport in 2009 and made the quarterfinals in ’08.

Isner replaced defending champion and top-seeded Mardy Fish, who withdrew when he was added to the US Davis Cup team.

In other first-round play, Donald Young defeated Paul Capdeville, 6-2, 6-1; Matthias Bachinger edged Dustin Brown, 7-6 (7-5), 6-7 (5-7), 6-1; and Ruben Bemelmans ousted Denis Gremelmayr, 6-4, 6-2.

The tournament is played in conjunction with Hall of Fame induction ceremonies that highlight the week. Andre Agassi will headline the 2011 class Saturday during a center-court ceremony.

Djokovic enjoys view Novak Djokovic received an adoring welcome in Serbia after his championship at Wimbledon and on his first day as the world’s top-ranked player.

Tens of thousands of fans chanted Djokovic’s nickname, “Nole, Nole,’’ as they gathered in front of the national assembly building in Belgrade at a boisterous welcoming ceremony.

Djokovic officially moved up from No. 2 one day after beating previously top-ranked Rafael Nadal, 6-4, 6-1, 1-6, 6-3, for his first title at the All England Club. It’s the first time in nearly 7 1/2 years that a man other than Nadal or Roger Federer is ranked No. 1.

“Times are changing,’’ said Djokovic, 24. “It’s good for the sport, I think, to have some new faces.’’

Safarova upended Russia’s Vesna Dolonts upset third-seeded Lucie Safarova of the Czech Republic, 6-3, 6-4, in the first round of the Swedish Open in Bastad. Aravane Rezai, last year’s winner, also advanced to the second round at the clay-court tournament by defeating Akgul Amanuradova, 6-2, 4-6, 6-3 . . . In Hungary, Klara Zakopalova defeated Han Xinyun of China, 6-0, 6-2, to advance to the second round of the Budapest Grand Prix . . . The International Tennis Federation is changing the dates for the 2012 and 2013 Davis Cup finals as part of a shorter calendar for men’s tennis. Next year’s Davis Cup final will be Nov. 16-18, two weeks earlier than originally planned, and the 2013 final will be Nov. 15-17. The ATP decided last year to extend the offseason for men’s tennis from five to seven weeks, starting in 2012.