Chris Ashton was sent off in the 49th minute as Worcester's nightmare season continued with a crushing 62-14 defeat to Northampton at Sixways.
The former England wing had earlier scored a Worcester try but his charge into a ruck saw his forearm make contact with an opponent's head to pick up a red card.
His departure sealed Worcester's fate as they fell to their 14th consecutive defeat, and they remain rooted to the bottom of the Gallagher Premiership table.
Ollie Sleightholme scored four tries for rampant Saints with George Furbank, Piers Francis, David Ribbans and Alex Mitchell grabbing the others. There was also a penalty try award, with James Grayson kicking a penalty and six conversions.
Ashton and Chris Pennell scored Worcester's tries, with Billy Searle and Fin Smith each adding a conversion.
Northampton suffered a severe blow when their Wales international Dan Biggar withdrew from the starting line-up with a minor leg injury picked up in training but they soon overcame that setback to take a third-minute lead.
Scrum-half Mitchell darted away to provide a sweetly-timed pass to Furbank, who burst clean through the home defence to score.
Northampton then suffered two setbacks in quick succession.
First they lost centre Rory Hutchinson, who was injured in tackling Lawrence, and then they conceded a try when the home backs combined well to send Ashton flying over in the corner.
Searle converted before Grayson put his side back in front with a straightforward penalty but Saints' injury woes continued when Furbank limped off.
Lawrence and number eight Joe Batley both make excellent 40-metre runs into the opposition 22 but Worcester showed their perpetual failing in not being able to make it count and the visitors made them pay.
Skilful handling sent Sleightholme flying down the right flank and he brushed off some weak tackling to score, with Grayson's conversion giving Northampton a 15-7 interval lead.
That advantage was extended two minutes after the restart as Saints scored a brilliant third try when quick passing sent Tommy Freeman away before the wing kicked in-field for Mitchell to collect and score.
Ashton was then sent off to end any hopes of a Worcester comeback, with Sleightholme scoring his second for the bonus point.
Saints temporarily lost their number eight Teimana Harrison to the sin-bin for a high challenge but it made no difference as Worcester conceded another try to Francis.
Francois Venter then deliberately knocked on to concede a penalty try and pick up a yellow card before Ribbans crossed, with Sleightholme taking his tally to four with two late tries to complete an embarrassing afternoon for Worcester.
Pennell had the final say with a last-minute try for Warriors.