Eddie O'Sullivan heaped praise on O'Connor after the game

The Wasps man celebrated his first cap with an outstanding display in the 17-12 victory over the Springboks.

O'Connor topped the tackle count and produced a masterclass in the loose.

"I was pinching myself after being selected and then couldn't believe my first cap was a win against South Africa," said the Galway native.

At 5ft 11in and 14st 3lbs, the Wasps flanker was the smallest forward on the pitch by some margin and was dwarfed by South Africa's monster back row.

But by the end of the afternoon his reputation had grown enormously although O'Connor later played down his efforts.

Match report: Classy Ireland stun South Africa

"I thought my performance was OK. In some parts of the match the occasion got to me, but I was happy enough at the end.

"People had mentioned the size issue but it's all about having aggression. I take a lot of aggression into every game and show a bit of passion as well."

O'Connor outshone his opposite number Schalk Burger - the Springboks flanker who has been earning rave reviews - and the 24-year-old drew a glowing tribute from coach Eddie O'Sullivan.

"I thought Jonny had a cracking game. He ran himself into the ground and threw everything he had at the Springboks. South Africa knew he was on the pitch," said O'Sullivan.

He had a cracking debut - as good as you could get Eddie O'Sullivan

"The great thing about Jonny is that he punches well above his weight.

"He was in there with the heavyweights and he gave as good as he got.

"He had a cracking debut - as good as you can get."

O'Connor was replaced by the bulkier Eric Miller in the 79th minute and the Galway-born forward admitted his first Test match had been a draining experience.

"This was a step up from club rugby. I was trying to do too much at the start and I put myself out of the game for a while, but then I found my feet and it was OK," he added.

Several Ireland players shed tears during the national anthem as they psyched themselves up for conflict but O'Connor used the occasion to settle his nerves - with a little help from his friends.

He said: "During the national anthem my mates were pointing over and trying to get a laugh out of me and that made me relax a bit, so I owe them some thanks."