Cape Town -The Stormers maintained their challenge in the Super 14 southern hemisphere championship with a bruising 21-8 win over the Cheetahs at Newlands on Saturday.

The win kept the Stormers in second place in the table, one point behind the Bulls, ahead of a bye next weekend which will be followed by a four-match Australasian tour.

Both teams were disrupted by injuries in a fast-paced, physical encounter marked by crunching collisions.

The Stormers were hit shortly before the kick-off when in-form flyhalf Peter Grant injured a thigh muscle during the warm-up and had to be replaced by veteran Willem de Waal.

The home side suffered another blow when fullback Joe Pietersen could not come out for the second half because of a muscle strain.

Pietersen scored all his team's points in the first half with two penalty goals, a try and a conversion, as the Stormers built a 13-5 lead at the break.

The Cheetahs lost two loose forwards, with Frans Viljoen suffering a suspected fractured cheekbone in the first half and flanker Hendro Scholtz going off with an ankle injury midway through the second half.

With Springbok flanker Heinrich Brussow sidelined by a long term injury, Cheetahs captain Juan Smith said he was concerned about the team's loose forward resources.

But he said the Cheetahs' defensive structure had worked well.

"We didn't use our chances," said Smith. "But they (Stormers) are an awesome team. I think they'll go a long way this season."

Stormers captain Schalk Burger said it was a typical physical battle between two South African teams.

"The break couldn't come at a better time for us," he said about his team's injuries.

"Hopefully we can nurse them and take them with us on tour."

After two early penalties by Pietersen, the Stormers mounted several waves of attacks through multiple phases before an overlap was created for the fullback to score the opening try.

The Cheetahs hit back with some superb interplay between centres Meyer Bosman and Robert Ebersohn, with Ebersohn collecting a chip ahead by Bosman and off-loading skillfully for his centre partner to score.

A dropped goal by Naas Olivier brought the Cheetahs to within three points but the visitors could not control the kick-off after their score and the Stormers worked the ball to the right for Jacque Fourie to go over near the corner.

Scorers:

Stormers - Tries: Joe Pietersen, Jaque Fourie. Conversion: J Pietersen. Penalties: J Pietersen (2), Willem de Waal.
Cheetahs - Try: Meyer Bosman. Drop Goal: Naas Olivier.