World number four Novak Djokovic and fourth seed Jo-Wilfried Tsonga advanced into the second round of the Halle Open tennis tournament on Tuesday.

Serbia's second seed Djokovic was barely troubled in overcoming Italian Simone Bolelli 7-5, 6-2 after 84 minutes' battle. He will meet Frenchman Florent Serra in the second round.

"For the first match on grass I played quite well," the 22-year-old told said. "I was coming from clay with a lot of sliding and you have to adjust. I think I did it alright."

World number nine Tsonga also progressed with a 7-5, 6-2 win over fellow Frenchman Fabrice Santoro and will now meet experienced German Tommy Haas.

(Xinhua News Agency June 10, 2009)