LV County Championship Division One, New Road
Worcestershire 237 & 5-0 beat Lancashire 161 & 80 by 10 wickets
Worcestershire 20pts, Lancashire 3pts
Richardson took eight wickets in the game
Worcestershire bowler Alan Richardson took six wickets as title-chasing Lancashire slumped to a 10-wicket defeat inside two days at New Road.
Having resumed their first innings on 209-6, the home team were eventually 237 all out - a lead of 76.
Richardson (6-22) and Kemar Roach (3-44) then tore through the Lancashire order, bowling them out for just 80.
That left Worcestershire needing just five runs to win and they took three balls to reach their target.
Having claimed the final four wickets of Worcestershire's first innings for 28 runs in the morning session Lancashire still harboured hopes of batting themselves into a winning position.
But they were without Stephen Moore who was absent to be with his pregnant wife.
And Richardson immediately had them on the back foot, removing Mark Chilton, Paul Horton and Karl Brown to leave them 32-3 at lunch.
That spell saw him take three wickets for eight runs in seven overs.
He picked up where he left off after the interval, dismissing Tom Smith and Gareth Cross in the space of three balls.
Roach, making his home debut, then hastened Lancashire's demise, ripping out Glen Chapple and Sajid Mahmood in successive deliveries.
Richardson trapped Steven Croft lbw before Roach bowled Kyle Hogg to complete Lancashire's misery.
The victory was Worcestershire's first against Lancashire in the County Championship since 1995 and boosted their hopes of avoiding relegation.
For Lancashire it was a major dent to their prospects of winning a first County Championship title in 77 years.
Worcester director of cricket Steve Rhodes told BBC Hereford and Worcester:
"The chaps have worked so hard all season, we have been in winning positions and not nailed it, but today we did.
"In a match where there were not many runs scored the part partnership between Ben Scott and James Cameron crucial and James played very well for his 98.
"They have played round the front pad and not played straight. We played a little bit away from our bodies and there are some technical areas we need to improve on.
"Neither side batted well on a wicket that was helpful for the bowlers but was certainly not a problem pitch."