Steyn, 37, took the kick, who settled the 2009 series and proved little has changed as he led the Springboks ahead with two more minutes.
The Lions took the lead in the first half after Kane. Instead, Owens tried and arranged from Finn Russell.
Cheslin Kolbe passes the ball and then goes down to the scorer.
Russell, who came in for Dan Biggar, injured in the 11th minute, went on to play the long run to tie things up at 13-13 with 18 minutes remaining.
He and Steyn then traded kicks before Springbok 10 managed a final blowout to add to their Lions series victory at the 2019 World Cup.
The victory ended in an impressive turnaround after South Africa lost their first Test. But there were no fans to celebrate at the Cape Town Stadium due to coronavirus restrictions.
The Lions had made it clear during the week that they wanted to play with tempo. They were stripped of that ability. But at least remained ahead on the scoreboard as Pollard missed two penalties.
The match was eventually revive as South Africa won the high ball once again and Willie le Roux drew Jack Conan in, giving Kolbe all the space he needed to run round Liam Williams and score.