Surrey 433 (Smith 138, Burns 79, Clark 78, Helm 6-110) and 78 for 2 (Jacks 45*) beat Middlesex 238 (Simpson 60, Holden 55, Abbott 3-37, Overton 3-45, Lawes 3-57) and 272 (Stoneman 72, Bamber 46*, Abbott 4-60) by eight wickets
Will Jacks struck a swift unbeaten 45 as Surrey motored to a comfortable eight-wicket victory over neighbours Middlesex inside an hour on the final morning.
The LV= Insurance County Championship front-runners needed only 11.1 overs to chase down a modest target of 78, completing their second derby success of the season and a first red-ball win at Lord's for 26 years. Middlesex, who remain second from bottom in Division One, have now lost four of their last five Championship fixtures.
"We were pretty clinical, I think, over three and a bit days," Rory Burns, Surrey's captain, said. "There are a few bits we could have tidied up on but, if you'd offered us that before the start of the game, we'd have taken it. Particularly after getting inserted on the first morning, to put up 433 as a batting group and then back that up by making them follow on - and the way we went about it - I think it's a big feather in our caps.
"I thought Jamie [Smith] played beautifully [in the first innings] and Jordan [Clark] was in pretty good nick as well. The way he came in and played was excellent, to get ourselves up to that sort of total was brilliant.
"It's a tough shift, any time you make someone follow on - I think we had about 150 [overs] in the dirt there, back to back. To take 20 wickets and keep being quite relentless over that period is a massive effort. Getting a wicket second ball [today] is always handy. The weather probably had a part to play in our chase as well, we were looking to get it done as quickly as we could."
With rain forecast for later in the day, Surrey were keen to secure the result as quickly as possible after bowling their hosts out for 272, with seamer Sean Abbott returning figures of 4 for 60.
Abbott took only two deliveries to finish off Middlesex's second innings when play resumed, banging it in short to last man Tim Murtagh, who could only fend it off into the slip area and Dom Sibley took the catch.
That left Ethan Bamber stranded on a career-best 46 not out and Surrey with 78 to score - just five more than the target they chased to complete a nine-wicket victory against Middlesex at the Oval in May.
First-innings centurion Smith was promoted to begin the chase with Burns, but he lasted just two balls on this occasion before clipping Tom Helm tamely into the hands of midwicket. Helm picked up a second wicket, his eighth of the match, when Burns attempted a paddle from outside off stump that was neatly taken by Murtagh at long leg, but Jacks maintained momentum by clouting Bamber over the cover boundary.
Tom Latham also struck a maximum off Helm before hitting the winning runs off Mark Stoneman to finish unbeaten on 21.