Seamer Toby Roland-Jones picked up 4-38 as Middlesex continued their excellent start to the season with victory over Surrey by an innings and 42 runs.
Surrey resumed on the third morning at 34-2 in their second innings, after being forced to follow-on at Lord's the previous evening.
And despite a defiant 94 from Steven Davies, the visitors slumped to 200 all out shortly before tea to complete a miserable performance
Roland-Jones cleaned up the tail after part-time seamer Neil Dexter had claimed a career-best 3-46, including the key scalp of Davies, whose 176-ball contribution contained 12 fours and a six.
Middlesex collected a 24-point haul for their efforts and sit proudly at the top of the LV County Championship Division Two table after three straight wins.
Surrey have made a real mess of things at Lord's as they were forced to follow on and still trailed by over 200 with two second wickets down against Middlesex.
John Simpson added just 17 to his overnight score to record 143 as Middlesex made 445 in their first innings, and they then turned their London derby massively in their favour by skittling out Surrey for just 203.
It could have been even worse had Tom Maynard not dug in, but he was let down by hi steam-mates as he was left two runs short of a deserved century on 98 not out and Surrey had to follow on.
In their second attempt, Surrey fared just as bad as they slipped to 34-2 at the close and still 208 runs behind heading into day three.
England seamer Steve Finn grabbed four wickets on the day, including back-to-back strikes in Surrey's second innings but being denied a hat-trick by Steve Davies.
Neil Dexter smashed 145 to help Middlesex recover from a shocking start to reach 368-5 by the close of the first day of their game against Surrey.
The hosts had fallen to 28-3 early on at Lord's but Dexter played a captain's innings to drag his side back into the game with a splendid knock alongside fellow centurion John Simpson.
22-year-old wicketkeeper Simpson and Dexter made a whopping 254 in 63 overs during their fifth-wicket stand, while Simpson went on to remain unbeaten on 126 at the close.
Dawid Malan initially helped Dexter to steady the ship in a stand of 60 for the fourth wicket, but when Malan (27) fell lbw to Gareth Batty 10 minutes before lunch, it looked as if Surrey were going to be rewarded for their decision to bowl first on a pitch with a hint of green to it.
Dexter skied an intended pull to mid-off to end his five-hour vigil leaving Simpson on a career-best score down the other end and Middlesex sitting on a cosy 368-5 at stumps.