The Lions clung on for a precious 33-30 victory against an injury-ravaged and determined Pumas side who nearly stole it at the death on Friday.
In a busy second half in which the lead changed three times, the Lions' stout defence denied the Pumas at the death as the latter made one effort after the other to cross the whitewash after the hooter - to no avail.
The Pumas had an option to kick a penalty smack in front of the Lions posts three minutes after the hooter sounded but they backed themselves by trying to run the ball in for a try. Had they goaled the penalty, the match would have ended in a draw.
Straight from the kick-off the visiting Lions kept the ball close to their forwards who kept ball in hand and ran the ball at every opportunity.
They gave no quarter as they thundered into the opposition's defensive lines and then, rather effectively recycled the crash-ball in several early multi-phase movements which saw the Pumas pinned down in their half.
With this impressive rampage unfolding there were ominous signs that the Lions were on the verge of a try fest but forward and spilt passes put paid to several threatening sorties.
However, the under-pressure Pumas' defence, as impressive as they were, fell foul of referee Joey Salmans, who awarded the Lions three penalties in the first 12 minutes.
Fly-half Francois Burton, a late inclusion for rookie Elton Jantjies who was nursing an injured foot and relegated to the substitutes' bench, goaled the first two penalties.
The Lions opted to run the third from in front of the posts and with the Pumas defence caught napping, right wing Deon van Rensburg streaked through for a converted try and a 13-0 lead.
The 13-0 setback seemed to sting the Pumas into all-out attack and whenever they managed to secure possession they put together some penetrative plays into the Lions' half.
Such was their confidence that they chose a line-out rather than go for the the three points in an 18th minute penalty in front of the Lions posts. The ploy paid dividends when they drove powerfully from the line-out and number eight Christo le Roux rounded off splendidly.
Fly-half Elgar Watts converted and moments later he was again on target with a penalty to reduce the deficit to three.
In the 10 minutes before the break the Pumas continued to impose themselves on the match with fine crossfield hand-to-hand movements but the Lions averted further woe to ensure that their slender three-point lead remained intact by the time the whistle sounded for half-time.
Play had hardly settled own in the second half when the Pumas struck with a vengeance to score 12 points in the opening eight minutes. First Watts dummied his way past for an unconverted try and six minutes later he converted a penalty try to give the Pumas the lead for the first time in the match.
The penalty try was awarded after Lions skipper and lock Franco van der Merwe was sin-binned after he grabbed Pumas centre Shaun Venter by his jersey's collar as the latter was running in to score a try.
The Lions struck back two minutes later after scrum-half Jano Vermaak charged down a Pumas clearance kick and pounced on the stray ball before running in to score. Francis fluffed the goalable conversion in the 49th minute.
The Pumas shook off the setback with some adventurous play in the ensuing minutes and they were rewarded with a bonus-point try through full-back Nicky Kritzinger who streaked at the corner. Watts' conversion failed, leaving it 27-18.
Kritzinger was sin-binned four minutes for a late tackle and the Lions made good in his absence when they rounded off splendidly with a try by flank Derick Minnie after a maul from a close-in line-out.
Francis' conversion narrowed the score to two points difference in the 63rd minute.
With both sides seemingly abandoning defence in search of a further score a frenetic passage of play followed in which the Lions managed to regain the lead six minutes ahead of the final whistle.
Pumas substitute fly-half Ricardo Croy stretched his side's lead with a penalty to 30-25, but the five-point cushion lasted a mere four minutes as full-back Jaco Taute snatched the Lions' bonus-point try which left scores level when Burton's conversion attempt failed. Though he made amends four minutes later with a penalty to regain the lead for the Lions.
Tries: Le Roux, Watts, penalty try, Kritzinger
Cons: Watts 2
Pens: Watts 2
Tries: Van Rensburg, Vermaak, Minnie, Taute
Pens: Francis 3
Pumas: 15 Nicky Kritzinger, 14 Vainon Willis, 13 Shaun Venter, 12 Tian Meyer, 11 Allistair Kettledas, 10 Elgar Watts, 9 Jacques Coetzee, 8 Christo le Roux, 7 Torsten van Jaarsveld, 6 Corné Steenkamp, 5 Marius Coetzer, 4 Andries Kruger, 3 Ashley Buys, 2 Hannes Franklin (c), 1 Ronnie Uys.
Replacements: 16 Dee-Jay Terblanche, 17 Dawie Steyn, 18 Willem Serfontein, 19 Jaco Bouwer, 20 Ricardo Croy, 21 Ashwin Scott, 22 Du-Wayne Smart.
Lions: 15 Jaco Taute, 14 Deon van Rensburg, 13 Waylon Murray, 12 Doppies la Grange, 11 Michael Killian, 10 Elton Jantjies, 9 Jano Vermaak, 8 Warren Whiteley, 7 Derick Minnie, 6 Renaldo Bothma, 5 Franco van der Merwe (c), 4 George Earle, 3 Ross Geldenhuys, 2 Edgar Marutlulle, 1 JC Janse van Rensburg.
Replacements: 16 Martin Bezuidenhout, 17 Wayne Swart, 18 Johan Snyman, 19 Joshua Strauss, 20 JP Joubert, 21 Burton Francis, 22 Jannie Boshoff.
Referee: Joey Salmans