Perth - Flyhalf Peter Grant scored the only second-half try in the 49th minute and kicked a shaky conversion to help give the Stormers a 17-3 win over the Force in a rain-drenched Super Rugby clash on Saturday.

The men from Cape Town led 7-3 at half-time before Grant's try and his subsequent conversion which clanged off the right goalpost into a successful two-pointer for the visitors.

It was the third win in four away matches for the Stormers, who have eight wins in nine matches ahead of next week's bye following their Australian and New Zealand road trip.

They have also regained top spot in the South African conference and moved into second spot on the overall log.

Centre Bryan Habana scored a controversial first-half try for the Stormers, converted by Grant, who also kicked a penalty for the winners.

Habana intercepted David Harvey's ambitious pass to score the opening try of the night in the 20th minute, running 60m before diving under the posts untouched.

But replays showed the ball slipped out of Habana's arms just inches short of the tryline, with the referees not close enough to see the mistake or ask for a video review.

As the match began, the Reds confirmed media reports that their Wallaby scrumhalf Will Genia had defected to the Force for next season.

"I believe Queensland Rugby made the best offer we could to retain Will's services in Queensland," Reds chief executive Jim Carmichael said in a statement. "However, the opportunity presented to head west was ultimately more appealing to Will."

Other media reported that Force captain and openside flanker David Pocock would turn down an approach from the Brumbies to remain in Perth.

Pocock said after the match that "nothing had been confirmed" about his or Genia's contracts.

He added about Saturday's match: "I don't think you can fault our effort, we came up against some good defence."

Lock Andries Bekker, who returned from injury to become the third captain in as many weeks for the Stormers, said his side adapted well to the slippery and wet conditions.

"I think we started off a bit slow," Bekker said. "We tried to throw the ball around a bit, but that didn't work in these conditions. So we relied on our defence."

Scorers:

Force:

Penalty: David Harvey.

Stormers:

Tries: Bryan Habana, Peter Grant

Conversions: Grant (2)

Penalty: Grant

Teams:

Force:
15 Alfie Mafi, 14 Rory Sidey, 13 Nick Cummins, 12 Winston Stanley, 11 Napolioni Nalaga, 10 David Harvey, 9 Brett Sheehan, 8 Ben McCalman, 7 David Pocock (captain), 6 Matt Hodgson, 5 Nathan Sharpe, 4 Toby Lynn, 3 Salesi Ma'afu, 2 Nathan Charles, 1 Pek Cowan

Substitutes: 16 Elvis Taione, 17 Salesi Manu, 18 Phoenix Battye, 19 Richard Brown, 20 Josh Holmes, 21 Ben Seymour, 22 Samu Wara

Stormers:
15. Joe Pietersen, 14. Gerhard van den Heever, 13. Bryan Habana, 12. Juan de Jongh, 11. Danie Poolman, 10. Peter Grant, 9. Dewaldt Duvenage, 8. Nizaam Carr, 7. Rynhardt Elstadt, 6. Siya Kolisi, 5. Andries Bekker (captain), 4. De Kock Steenkamp, 3. Frans Malherbe, 2. Tiaan Liebenberg, 1. Steven Kitshoff
 
Substitutes: 16. Scarra Ntubeni, 17. Brok Harris, 18. Don Armand, 19. Deon Fourie, 20. Louis Schreuder, 21. Burton Francis, 22. JP du Plessis