China's Olympic light flyweight champion Zou Shiming made a winning start at the world boxing championships, beating Juan Medina of the Dominican Republic in the event's opening day here on Monday.
The 30-year-old veteran, who is seeking his third world title here after winning the 2005 and 2007 editions of the event, is also aiming to obtain a place at the 2012 London Games.
Zou, China's most accomplished fighter, who is unbeaten since 2007, when he lost to Mongolia's defending world champion Purevdorj Serdamba, will face Hungary's Istvan Ungvari, who had an opening round bye, in the second round.
Cuba's young prodigy, 19-year-old Yosvany Veitia, who won the bronze medal at the youth world championships, also breezed into the next round beating Birzhan Zhakypov of Kazakhztan, bronze medalist at last year's Asian Games.
Meanwhile, the 21-year-old Argentinian Junior Zarate also advanced into the next round after overcoming Charlie Edwards of England by just two points in a tough bout 17-15, clinching the deciding points in the final round.
In the event's heavyweight category another Cuban fighter Jose Angel Larduet, former youth world champion and one of the hot favourites, also breezed into the next round as he disposed of Lubos Velecky of Czech Republic.
Mexica's Maria Heredia Orrantia recorded an early win over the Spaniard Juan Agustin Oliva Aleman clinching a commanding 17-3 victory and will meet top seed Artur Beterrbiev of Russia in the next round.
Ihab Almatbouli of Jordan was in complete command in his bout with Denmark's Peter Pedersen winning it with the best punch difference of the day 30-9.