Waterloo 42 Stourbridge 19
Stourbridge's plight deepened after defeat by promotion candidates Waterloo at Blundellsands was accompanied by victory for fellow strugglers Blackheath over previously high-flying Berking.
It leaves Stourbridge with only Halifax within overtaking range to escape the relegation zone and the northerners have a match in hand - to be played next Saturday at home against bottom-placed Orrell.
Waterloo led after five minutes with the first of three penalty goals by Steve Nutt, who also converted all but the last of the Liverpudlians five tries for a personal tally of 22 points.
Stourbridge did most of the early attacking but home centre Freeman Payne intercepted a mis-pass by young fly half Sam Robinson to score from 75 yards before scything through missed tackles for his second try.
Nutt's second penalty on 25 minutes made it 20-0 before Waterloo's volatile No. 8 Njike Tchakoute was sent off for a dangerous high tackle on winger Jon Hall.
Alistair Bressington kicked the resultant penalty for Stourbridge and added two more to punish Waterloo offsides and reduced the lead to 29 but Nutt ended the first half with his third penalty.
Frequent Waterloo pressure created midfield gaps, first exploited by left winger Craig Aikman, who cut inside for a try between the posts.
A splendid long break by centre Marcus Cook was capped with the first Stour-bridge try by supporting fullback Bressington, who failed to convert, and Waterloo soon forged ahead again.
When first fly-half Nutt split the visitors' defence for the fourth home try, then right winger Neil Kerfoot did likewise, Waterloo were 42-14 up and cruising by the hour. Right winger Toby Wilson got Stourbridge's second unconverted try after a searing run by Greg Summers.
