McGivern kept the momentum going in round two, with well-timed single blows and combinations stunning Takacs, on the way to a 30-26, 30-27, 30-27, 30-27, 30-27 triumph in the 64kg contest.

After his unanimous points win, McGivern said: “It’s great to get the first one out of the way, as the first one is always hard.

“You’re always kind of nervous until you get into the ring, and see what the arena is like.

“I caught him early with a body shot, I knew that was going to work - the coaches told me it was going to work and it did.

“I think I had better punching today, I hurt him in the second round.

“Now I’m just going to keep on going, take it fight by fight, round by round, and hopefully get to the final.”

McGivern next fights Armenia’s European light-welterweight champion and world bronze-medallist Hovhannes Bachkov in Tuesday’s round-of-16

A terrific performance from Michael Nevin saw the middleweight beat Rio Olympics bronze-medallist Kamran Shakhsuvarly of Azerbaijan again on a unanimous decision.

A suitably solid start from Nevin saw him take an early advantage, and though Shakhsuvarly recovered and got some headway back into the contest, Nevin ramped the pressure up again towards the end of round 1.

A strong second round from the Portlaoise fighter probably made Nevin aware that a significant win was on the way, as he tested Shaksuvarly, taking control as the fight wore on.

After winning 5-0 on the judges’ scorecards (30-27, 30-26, 29-28, 29-28, 30-26), Nevin said: “I’m feeling really good, I can’t wait for the next fight now.

“I’m very happy with the performance and I’m feeling strong.

“We had a good plan beforehand, and it went well. I’ve a few days’ break now, so I’ll be feeling good and fresh after that.”

Nevin next has a quarter-final on Tuesday against Turkey’s Serhat Güler, another World Series of Boxing veteran.

Buckley enjoyed a unanimous victory himself at light-flyweight over 2015 European Games champion Bator Sagaluev of Russia in a remarkable last-16 triumph.

Sagaluev, who beat Brendan Irvine in the Baku decider, was under pressure from the start against Buckley, and was noticeably tiring as the intense contest wore on.

“I’d be able to go out there again right now,” Buckley beamed in the aftermath of his shock win.

“Building from this now will be the important thing.

“The first round, I felt I caught him with some nice shots and I got my timing straight away, which was great.

“The second round? I was doing what my coach was telling me, and everything worked. “The third round was a bit of a brawl. I could see he was getting tired, so I was trying to push on the gas and my coach was telling me to get back out and box again – so I did.

It doesn’t matter who’s next – I’m going for gold.

Buckley next faces Spain’s WSB fighter Martin Molina in Tuesday’s quarter-finals.

Dublin’s Tony Browne was dispatched on a 4-1 split decision by Croatia’s Tony Filipi at heavyweight – three of the judges marking it 29-27 in favour of the Mediterranean Games champion in their last 16 encounter.

Browne said: “I’m very disappointed. One punch can change a fight. It was close, but obviously receiving a count during the fight cost me the decision.”