The Lions got their tour of South Africa off to a winning start with a 22-17 victory in Cape Town.
Dan Biggar's penalty just past the hour mark proved to be the crucial blow and ensure the first match of the series went to Warren Gatland's men.
The Springboks had led for much of the match, having got their noses in front first when Handre Pollard converted two penalties just four minutes apart to give them the early advantage.
Lions' fly-half Biggar then halved the deficit with a penalty of his own, but Pollard bagged another six points as the hosts opened up a significant gap.
Biggar then spurned the chance to pull his side back into it as his kick went wide of the posts, before Elliot Daly missed with a long-range penalty as South Africa held a nine-point advantage at the break.
The Lions were first to strike in the second half though, forcing the ball over the line with a driving maul as Luke Cowan-Dickie got the first try of the series, with Biggar's conversion bringing the Lions within two points.
It looked as though South Africa had hit straight back moments later when Willie le Roux scored a breakaway try, only for a TMO review to determine he was offside as the effort was ruled out.
There was no such luck for the Lions shortly after, though, when Faf de Klerk's try was allowed to stand after the video referee saw no issue with the build-up, despite a hint of a knock-on.
Pollard's perfect record was then dashed as he missed his conversion, as the tie then swung back in the Lions' favour.
Three successful penalty kicks in succession from Biggar put Warren Gatland's men ahead for the first time in the contest as the South African's were punished for their indiscipline.
Owen Farrell then converted a late penalty to give the Lions slight breathing space as they held out for the win.
Reflecting on the win, Lions' captain Alun Wyn Jones said: "We are aware this is a first game in a series of three. In the second half we did not force as much on the kick counter, the set-piece came into the game and we got reward."
Opposing skipper Siya Kolisi conceded the amount of penalties they had given away had cost South Africa.
"We started well in the first half, but there is a lot we have to work on, with our discipline being number one," Kolisi said. "The set-piece and mauls, we could have done better, we made a couple of technical mistakes. We will go back and look at that.
"We must fix what we can as a team, we must make sure we come back better and stronger next week. We at least have another game under our belt."
