Grant will come up against the skilful Frenchman Frederic Michalak when the Stormers and the Sharks lock horns in the semi-final at Newlands on Saturday.
The Springbok captain told Die Burger he's more than happy with "Bash" - as Grant is known to his team-mates - at his side.
Grant has a staggering goal-kicking record this season. He's been successful with 45 out of 48 kicks at goal - a 94% strike rate.
"I believe Peter Grant is our best player this year. He clinched games in our favour, and it was his penalty (from the corner in the dying minutes) which helped us beat the Sharks (15-12) earlier this year at Newlands."
De Villiers did, however, note that Michalak is a dangerous player they'll need to keep their eyes on.
"Fred is a flamboyant player. He can swing the outcome of a match and with Charl McLeod (scrumhalf) on his inside, they have good halves," said De Villiers.
The clash at Newlands kicks off at 17:05 on Saturday.
Teams:
Stormers: 15. Joe Pietersen, 14. Gio Aplon, 13. Juan de Jongh, 12. Jean de Villiers (captain), 11. Bryan Habana, 10. Peter Grant, 9. Dewaldt Duvenage, 8. Deon Fourie, 7. Rynhardt Elstadt, 6. Siya Kolisi, 5. Andries Bekker, 4. Eben Etzebeth, 3. Brok Harris, 2. Tiaan Liebenberg, 1. Steven Kitshoff
Substitutes: 16. Frans Malherbe, 17. Deon Carstens, 18. De Kock Steenkamp, 19. Don Armand, 20. Louis Schreuder, 21. Burton Francis, 22. Gerhard van den Heever
Sharks: 15 Louis Ludik, 14 JP Pietersen, 13 Tim Whitehead, 12 Meyer Bosman, 11 Lwazi Mvovo, 10 Frederic Michalak, 9 Charl McLeod, 8 Ryan Kankowski, 7 Marcell Coetzee, 6 Keegan Daniel (captain), 5 Anton Bresler, 4 Willem Alberts, 3 Jannie du Plessis, 2 Bismarck du Plessis, 1 Tendai Mtawarira
Substitutes: 16 Craig Burden, 17 Wiehahn Herbst, 18 Steven Sykes, 19 Jean Deysel, 20 Jacques Botes, 21 Odwa Ndungane, 22 Riaan Viljoen
