Another second half slump has left Danny Wilson's side desperate to take points from next week's clash with the Bulls

Jack Dempsey crossed for Warriors but Rikus Pretorius replied and Stormers led 13-7 at the interval.

Further tries by Herschel Jantjies and Leolin Zas extended the hosts' advantage.

The visitors had Josh McKay sin-binned and Evan Roos got a bonus-point winning try for Stormers.

The South African side's sixth successive win moves them to within eight points of Leinster and two ahead of Glasgow.

Warriors now face a struggle to secure a home play-off spot but the defeat could be even more costly with Kyle Steyn and Sam Johnson being forced off through injury.

Steyn left the field early with an achilles injury, while Johnson damaged an ankle in the second half. It is not yet known how bad either injury is.

"We need to go and take points now from the Bulls game," head coach Danny Wilson said after the match. "We've been top four all season and knew that these last three games were going to be huge.

Wilson did not try to make excuses after another match in which his team faded badly in the second half.

"It's a common theme," the head coach added. "We struggled with a little bit of adversity and made too many errors - that's the cycle that we now need to break. We've been good for 40 minutes in most games; second halves haven't been as good. It is definitely something that we need to look at."