Auckland - Fly-half Peter Grant kicked seven goals from seven attempts for 18 points as South Africa's Stormers beat the Blues 33-21 in Super 14 rugby on Saturday.

The Stormers, coming off a surprise eighth-round loss to the Western Force, shot to a 20-0 lead after 32 minutes with tries to centre Jaque Fourie and halfback Dewalt Duvenage and on the back of Grant's fail-safe kicking.

The Blues closed to 23-14 and 30-21 with tries to Luke McAlister and Joe Rokocoko but were forced to play catch-up rugby against a Stormers team which produced superb defence.

Blues dropped to 4-4 for the season while the Stormers remained firmly in the top four with a 6-2 record.

"Last week we slipped up badly against the Force," Stormers captain Schalk Burger said. "But I'm very proud of the way the boys stepped up.

"It was important for us whenever we had the ball to get points because the Blues are such a good attacking team."

The Stormers were led Saturday by outstanding performances from fullback Gio Aplon, centre Fourie and halfback Duvenage in the backs and by lock Andries Bekker and hooker Tiaan Liebenberg in the forwards.

They played with precision at lineouts and scrums and were a more effective attacking unit than the Blues, whose game was plagued by elementary mistakes.

The Stormers also showed the form that has made them the best defensive side in the Super 14 this season, repeatedly shutting down dangerous Blues attacks. The Stormers have allowed only 96 points in eight matches, the fewest by nearly 100 points among teams that have played eight or more games.

"We were slow to capitalize on really good opportunities, especially in the second half," Blues captain Keven Mealamu said.

"They're the top defensive side in the competition and they force you to take risks and make mistakes."

Grant kicked conversions of tries by Fourie, Duvenage and lock Anton van Zyl and added four penalties.

The Blues scored tries through flanker Serge Lilo, McAlister and Rokocoko but, after the Stormers' strong opening 30 minutes, never led.

Scorers:

Stormers 33 - 21 Blues (Halftime 20-7)

Stormers - Tries: Jaque Fourie, Dewaldt Duvenage, Anton Van Zyl; Conversions: Peter Grant (3); Penalties: Grant (4)

Blues - Tries: Serge Lilo, Luke McAlister, Joe Rokocoko; Conversions: Stephen Brett (3)