Vijender (75 kg), Mandeep Jangra (69 kg) and L Devendro Singh (49 kg) came up with dominating victories in the men's competition, while L Sarita Devi (60 kg) and Pinki Jangra (51 kg) entered the last four of the women's event.
Vijender, the 2008 Olympic bronze-medallist, outclassed Trinidad and Tobago's Aaron Prince, winning 3-0 on points in a unanimous decision. (Also read: Complete list of India's medal winners on July 30)
"I changed my tactics midway in the bout. In the first round I was trying to play a bit defensively. But he kept on coming and so I had to change my tactics and become aggressive," said the former World Championship bronze medallist.
"It is all about doing right things during the bout. I took some punches from my opponent but it was all about boxing. You get hit. I am getting better and hope I win gold," added the former world number one.
The first round was a bit subdued with both the boxers trying to get a measure of each other. Vijender was the more defensive of the two in the opening three minutes.
In the second round though, Vijender picked up pace and caught his rival off guard with a flurry of punches for which Prince had no response. A straight jab and then a right hook from Vijender rattled Prince.
The tempo continued in the third round and Vijender won comfortably in the end. On his comfortable win, Vijender said, "It was an open fight but my opponent was also very tough. I never underestimated him but I never thought I was ever in any real danger either."
Asked about the semifinal, he said, "Once you get to a semi-final in any competition, you really have to be at your very best and you prepare for that the way you would prepare for the gold medal fight. "I'm going to be up against Connor Coyle (Nigeria) and that will be a very big challenge for me, but I am feeling really great."