"I think it's a big wake-up call for us" O'Connell told Sky Sports immediately after the final whistle of his first game as Lions skipper.
"We've been working hard on getting used to playing with each other but you have to remember what you need to bring to a rugby match as well - the physicality and the attention to detail."
The Lions needed late scores from Alun-Wyn Jones and Ronan O'Gara to secure an invaluable victory as they overturned an 18-3 and 25-13 deficit to get the 10-match tour off to a winning start.
O'Connell, who played in all three Tests for the Lions against the All Blacks four years ago, recognises that the Lions now have plenty of areas to work on before facing the Springboks.
But the 29-year-old says there is more than enough character within the group to ensure that his squad will move onward and upwards over the coming five weeks, starting with next Wednesday's clash with the Golden Lions in Johannesburg.
"We just couldn't get any phases together because we kept making mistakes. It was a struggle but we dug deep and got the win," added O'Connell.
"It's hard when you're just coming together as a team but we're trying to get beyond that now and focus and improve on Wednesday.
"Cutting down the mistakes is going to be a big thing. I'm not sure whether that's concentration or apprehension but you can't make that many mistakes no matter who you're playing.
"We've all had bad games, we've all gone out there and had nightmares, but we've just got to put it behind us. We've got a good squad, a good bunch of friends here and I think the boys will be fine."