The late wickets of Sam Robson and Chris Rogers left Middlesex reeling at the close of day one of their LV=County Championship match against Durham in Chester-le-Street.
Middlesex's bowlers had earlier responded to captain Rogers' decision to bowl first by dismissing their opponents inside the opening day.
Corey Collymore was the pick for the visitors, finishing with figures of 4/61 as Durham fell from 205/5 to 259 all out, having earlier also been 108/1.
James Harris bowled impressively, taking the wickets of England trio Paul Collingwood, Ben Stokes and Phil Mustard while there were wickets for medium-pacers Gareth Berg and Neil Dexter.
Wicket-keeper Mustard top scored for the North East county and was last out for 62 and there was a half century for in-form number three Scott Borthwick.
Durham then finished the day on a high against their top-of-the-table opponents, with Graham Onions taking the wicket of the in-form Robson in the first over and Callum Thorp following up with the key dismissal of Ashes Series bound Rogers.
Nightwatchman Tom Smith helped Joe Denly reach the close with the damage limited, but at 11/2 and with their two most prolific batsman so far this summer already dismissed, the hosts will sense blood on the second morning.