Olympian Sumit Sangwan in 81kg category and Vikash Malik in 60kg category entered the pre-quarter finals of the World Boxing Championships in Almaty, Kazakhstan today. While Sumit stunned ninth seed Petru Ciobanu of Moldova 2-1, Vikash got the better of Poland's Dawid Michelus by the similar margin. On Saturday, national champion Satish Kumar in +91kg category also booked a prequarters berth when he defeated Tajikistan's Mirodzhidin Karimov 3-0 in the openinground.