Western Province ended the Sharks' unbeaten run when they claimed a 34-27 bonus point win in Cape Town on Saturday.
It was an arm-wrestle from the outset as the lead changed hands throughout the game but Western Province were able eventually secure the win after a powerful display from their forwards.
The result sees the home side jump up to sixth on the table as they leap-frog their Cape rivals, Boland. They
match the Golden Lions' 12 points but stay behind the champions since the Lions have a better points difference.
The Sharks lose their grip on the table after the Cheetahs' win over the Kings. The Sharks and Cheetahs are tied at the top with 19 points, again only points difference separating the two sides.
The most noteworthy competition of the clash was Western Province flyhalf Robert du Preez versus Sharks full-back Curwin Bosch. Du Preez produced a mercurial performance as his clever dinks over the Sharks led to host a of tries for his team.
Bosch was magnificent off the tee as he very calmly got his side back into the lead in the first half through four perfectly executed kicks.
Western Province opened up their account in the first three minutes when Johnny Kotze busted through the Sharks line to score under the posts.
The home side then added to their tally after flyhalf Robert du Preez kicked a perfectly weighted cross kick for former Blitzbokke Sevens star Werner Kok to pluck out of the air and run in for the try.
The Sharks closed the lead on their hosts after three penalties from Bosch and then a wonderfully worked try when Sharks fly-half Inny Radebe took the ball to the line and then gave it wide for Jean-Luc du Preez to gather and dive over the line.
Bosch then equalised the scoring after the Sharks were awarded a penalty 40 metres out and the youngster made no mistake in knocking it over. He then took another shot at goal to give the visitors the lead.
EW Viljoen then got his side back into the lead after Du Preez unleashed another great cross kick and Viljoen outjumped Bosch to claim the kick and the try.
Sharks flanker Du Preez went from hero to villain after he tip tackled a Western Province player and was given a yellow card.
Western Province received the four-try bonus point when they set up a powerful maul on the Sharks 22 metre line and drove all the way to the Sharks' try line before just being taken down. Kobus van Dyk was given a blindside pass and dived over the line.
Province consolidated the score after Viljoen scored his second try of the game after flyhalf Du Preez kicked through a cheeky grubber behind the Sharks defence which Viljoen collected to score.
The Sharks ended off the scoring when they drove the ball wide before Rhyno Smith was given the pass and took it over the line with ease.
For Western Province:
Tries: Kotze, Kok, Viljoen 2, Van Dyk
Cons: Du Preez
Pens: Du Preez 2
For the Sharks:
Tries: Du Preez, Smith
Pens: Bosch 5
Yellow Card: Du Preez
Western Province: 15 Cheslin Kolbe, 14 Werner Kok, 13 EW Viljoen, 12 Johnny Kotze, 11 Leolin Zas, 10 Robert du Preez, 9 Jano Vermaak, 8 Sikhumbuzo Notshe, 7 Kobus van Dyk, 6 Stefan Willemse, 5 Chris van Zyl (captain), 4 JD Schickerling, 3 Wilco Louw, 2 Scarra Ntubeni, 1 JC Janse van Rensburg.
Replacements: 16 Neil Rautenbach, 17 Alistair Vermaak, 18 JP Smith, 19 Jan de Klerk, 20 Jurie van Vuuren, 21 Dewaldt Duvenage, 22 Scott Van Breda
Sharks: 15 Curwin Bosch, 14 Odwa Ndungane, 13 Lukhanyo Am, 12 Andre Esterhuizen, 11 S’bura Sithole, 10 Inny Radebe, 9 Stefan Ungerer, 8 Philip van der Walt, 7 Jean-Luc du Preez, 6 Keegan Daniel (c), 5 Ruan Botha, 4 Etienne Oosthuizen, 3 Thomas du Toit, 2 Franco Marais, 1 Juan Schoeman
Replacements: 16 Chiliboy Ralepelle, 17 John-Hubert Meyer, 18 Jean Droste, 19 Jean Deysel, 20 Michael Claassens, 21 Heimar Williams, 22 Rhyno Smith
Referee: Rasta Rasivhenge
Assistant Referees: Quinton Immelman, Jaco Kotze
TMO: Marius Jonke