Australia's Kurtley Beale and Lions full-back Leigh Halfpenny had chances to win the first and second Tests respectively with the last kick of the game but both came up short.
Halfpenny's miss in Melbourne meant it was Leali'ifano's nerveless conversion of Adam Ashley-Cooper's 75th minute try that gave the Wallabies a 16-15 victory to level up the series.
The kick gave him a flawless four from four record and capped a superb night for the 25-year-old in what was effectively his debut after a concussion ended his first Test in the first minute of the 23-21 defeat in Brisbane.
His ACT Brumbies captain and Wallabies team-mate Ben Mowen says that, but for injury, the New Zealand-born centre would be a 30-40 Test Wallaby by now and both struggled to recall an instance where he had missed a clutch kick.
"I haven't ever really missed one in a crucial situation," said Leali'ifano, who moved to Melbourne as a child.
"I've been very lucky in that regard. I learn from every kick in terms of keeping my composure.
"I've always spoken about going through the same processes as if I was kicking in the backyard. I'm lucky enough that I'm strong enough to really, truly focus and not let the pressure get to me."
Although he trusts his processes, Leali'ifano also derives strength from a green wristband that commemorates a friend who died last year and a tattoo in memory of his father, who passed away in 2006.
After his early departure from the pitch in the first Test, he has added a dash of superstition to his pre-match routine.
"In the captain's run last week, Adam Ashley-Cooper said you've got to tweak something so I took my socks and shorts home from the captain's run, which I've never done before, I think I'll be doing that every game," he laughed.
Mowen, who also made his debut in the first Test, believes Leali'ifano's transition from Super Rugby to Test stage has been seamless and would not hesitate to toss him the ball if the series comes down to one kick.
"If it comes down to goalkicking in the end once again and the ball gets handed over to someone like Christian Leali'ifano then your comfort levels go up a little bit," he said.
"I think it just comes down to how centred he is as a bloke. He's a very balanced guy off the field, a very mature guy, I think he's had four or five kicks to win games over the last two or three years and I think he's kicked every one of them.
"That's an amazing stat. He's pretty funny because he says whenever I throw the ball to him to kick a winning goal, I don't look him in the eye because I don't want to put more pressure on him.
"But whenever I've had to do it, you hand it to him knowing it's going to have a good result and that's an amazing trait to have."