Lawrence states his claim
The 27-year-old Stoke midfielder's pinpoint 37th-minute free-kick was enough to see off the challenge of Joel Santana's side and hand manager Giovanni Trapattoni a second victory inside four days. Perhaps more significantly, it was achieved without eight of the men who started Saturday's Group 8 win in Cyprus to demonstrate that there are reinforcements in the Irish camp for the bigger tests to come.
For Lawrence, it was the perfect opportunity to prove to Trapattoni that he has what it takes to play a role in next month's decisive qualifiers against Italy and Montenegro, and beyond, if the Irish do make the finals. He said: "It plants a seed in his head for the next qualifier, so hopefully I will be involved again.
"It was not a second string, but there were a few fringe players thrown in tonight, including myself, and it was important we went out there and gave a good account of ourselves, and I thought we did that tonight. I was just dying to get involved. I was disappointed on Saturday not being involved, but you just have to channel that into the right areas and work hard in training and wait for your chance, and I have done."
As good as it was, Lawrence's winner came against the run of play as the South Africans dominated the first half with some fluent and enterprising football. But crucially, they did not take their chances, and Lawrence, winning just his second senior cap, made them pay in fine style with his first international goal.
He said: "I caught it well and luckily it went in - and it ended to be the winning goal, so I am delighted. We did a lot of them yesterday and practised quite a bit, and a few were going wide and over the bar yesterday. But thankfully, today it went in."
Trapattoni will leave Ireland tomorrow morning a satisfied man as he heads for Turin and tomorrow night's showdown between his native country and third-placed Bulgaria, a match which could have a major say in Ireland's FIFA World Cup destiny.
He will do so having had a chance to see Keiren Westwood, Stephen Kelly, Eddie Nolan, Lawrence, Darron Gibson, Andy Keogh, Caleb Folan and substitute Leon Best, who proved a real handful in the closing stages, get some serious football under their belts on the big stage. Trapattoni said: "You asked me what I expected of me from this match - it was important that three or four of the young players got to play.
"I wanted to see their qualities. I knew Lawrence has quality and I saw that, and Keogh played a good game. I wanted to see the team compact and that the players know our system, our movement, with or without the ball. If there is no organisation on the pitch, it is impossible to get the result."