The Belfast man, one of the favourites to win gold in the bantamweight division, lived up to his reputation by winning the first two rounds comfortably against Matthew Martin of Nauru.
However the victory wasn't entirely painless as a clash of heads between the two fighters in round three left Conlan's face streaked with blood.
It has led to more questions being asked about the banning of head guards for men in the Games for the first time in 32 years.
Conlan said: "I loved fighting with the head guard but cuts are going to be dangerous when you turn professional so you're better off learning now.
"Boxing is just going to have to get used to it."
The 22-year-old overcame the scare and went on to secure a unanimous points win and the cut is not expected to damage his medal chances.
Belfast fighter Ruairi Dalton was also in action on Friday - he secured a unanimous win against Zambia's Christopher Katanga to reach the last 16 of the men's fly 52kg.
He said: "It's good to get in there and get the win, that's the main thing. There is a lot of pressure, you want to keep on winning and you don't want to let anyone down but that spurs you on. I'm going for gold. The support from the crowd was brilliant, it felt like home."
And Ballymena man Steven Donnelly made it three wins out of three for the Team NI boxers as he knocked out Hasan Asif of Pakistan after 37 seconds of their men's welter 69kg clash.
He said: "I trained tremendously hard for this and as you saw in the first round it all paid off. But I'm not going to get carried away, it's only the first round and I have a hard second round ahead."
Meanwhile in judo, Eoin Fleming missed out on a bronze medal despite putting in a commendable performance against Jacques van Zyl of South Africa.