But British and Irish Lions fly-half O'Gara - on as a replacement for Jonathan Sexton - sent over a late drop-goal to bag a 13-11 win and leave Kidney unsure whether to laugh or cry.
"Obviously when it gets that close to the wire it's a relief but I'm delighted to see the belief coming through from the players in the last two minutes," said Kidney. "That's the one thing you can't coach.
"For the first 60 minutes the execution wasn't great. We were creating chances that we couldn't take but I must say that didn't come as a shock to me as Italy's scramble defence is excellent.
"I'm not hiding behind the fact that we were far from perfect. The players are all working hard.
"There's a mixture of relief at having got the result but also disappointment at the performance.
"We're possibly guilty of trying too hard, like in the autumn series against South Africa, but this time the guys calmed down and realised we don't need to force it quite as much."