Miami (AFP) - Serena Williams crushed a teenaged talent less than half her age Sunday to reach the fourth round of the ATP and WTA Miami Open, defeating American Catherine Bellis 6-1, 6-1.The 15-year-old US challenger was no match for the 33-year-old American, a 19-time grand slam champion who is bidding for a record eighth trophy at her home event.Bellis, the junior world number one, found herself in a major test against the game's current dominator in her first WTA appearance since the US Open, where she upset Dominika Cibulkova.World number one Williams is competing in Miami for the 15th time since debuting as a teenager herself in 1998, a year before Bellis was born.Top-seed Williams will next face Russian Svetlana Kuznetsova, a winner over German 13th seed Angelique Kerber 6-3, 3-6, 6-3.Williams, bidding for a third consecutive Miami title, stretched her win streak to 14 matches at Crandon Park.