Three tries before the break gave Province the platform they needed to score a win which would enable them to move into the play-off zone ahead of the Blue Bulls. Province will join the Golden Lions, the Cheetahs and the Sharks in next week's semi-finals.
Province were adventurous at the start as they tried to run the ball at every opportunity, including one instance when they secured a turn-over on their own 22-metre line and played the length of the field for their opening try in the third minute.
Province's approach was probably influenced by the Blue Bulls' 92-21 rout of the Leopards on Friday. The Bulls' bonus-point win enabled them to displace Province in fourth position on the latest standings as well improve their points difference substantially.
Centre Jean de Villiers scored the third-minute touch and hooker Deon Fourie followed suit seven minutes later, after which flyhalf Demetri Catrakilis added a second conversion (14-0).
At this stage there were ominous signs that Province were also headed for a 90-pointer but the Pumas stormed back with strong runs upfield from the set-pieces, and Province were kept quiet for a 20-minute spell as they were forced on the defensive.
The Pumas' attacking efforts were rewarded with a try by flank Jaco Bouwer in the 16th minute and flyhalf Carl Bezuidenout added a conversion and a 24th minute penalty. During that passage of play, Catrakilis reduced the deficit with his first penalty in the match (17-8).
The final 10 minutes before half-time saw Province regain the initiative and as long as they kept the ball alive with crisp inter-passing movements the Pumas defence was at risk.
Centre Juan de Jongh rounded off splendidly when the Pumas defence opened up and Catrakilis goaled the conversion to give the home side 24-8 lead at the break.
As is their custom, the Pumas discarded the pink glow jerseys in the second half in favour of their traditional black and red strip and the change seemed to lift their game as Province battled to get their hands on the ball. However, the Pumas' only reward was another Bezuidenhout penalty (24-11).
Just ahead of the hour mark, Province brought on Schalk Burger to a roaring applause from the 15 000-strong crowd, and he was later joined by fellow replacements, Tiaan Liebenberg, Tertius Danilier and Jaque Fourie.
The fresh legs gave Province the injection they needed to shake off the Pumas hold on the game and flanker Siya Kolisi snatched the bonus-point try, which went unconverted, on the hour mark (29-11).
Once Province had reached this objective they celebrated their final 20 minutes of 2011 rugby at Newlands by keeping the ball alive but the Pumas never-say-die attitude came to the fore as the home side who, despite a surfeit of possession, were restricted to just a solitary try. Wing JJ Engelbrecht was the scorer and fullback Conrad Jantjes, who ended the match in the flyhalf position, added the conversion (36-11).
In the final 10 minutes, both teams seemed to abandon defence but with errors creeping into play at every turn the most promising of scoring moves were stifled, except one which ended in a try for Bryan Habana who signed off rugby for the 2011 season at Newlands. Jantjes converted (43-18)
Scorers
Western Province: Tries: Jean de Villiers, Deon Fourie, Juan de Jongh, Siya Kolisi, Bryan Hbana, JJ Engelbrecht. Conversions: Demetri Catrakilis (3), Conrad Jantjes (2). Penalty. Catrakilis.
Pumas: Tries: Jaco Bouwer, Reginald Kember. Conversion: Carl Bezuidenhout.
Penalties: Bezuidenhout (2)