Middlesex are 44 runs short of victory after bowlers again dominated on the second day of their Division One clash with Durham at Lord's.
Graham Onions took his haul to seven wickets in Middlesex's first innings but the visiting batsman failed to pass 200 for the second time in setting the hosts a target of only 147.
A total of 15 wickets fell on the first day at the Home of Cricket and England discard Onions made sure that trend would continue in an inspired morning spell.
He accounted for the unbeaten batsman - Neil Dexter (48) and Gareth Berg (35) - both of whom were caught behind, as were Ollie Rayner and Tim Murtagh.
Onions ended the Middlesex innings on 168 when Michael Richardson held on to a catch to dismiss Steve Finn for four, finishing with figures of 7-62.
But Murtagh and Finn were soon among the wickets themselves with Mark Stoneman failing to trouble the scorer and Keaton Jennings making only two before another discarded England bowler struck.
Steve Borthwick made 26 before Murtagh claimed his second wicket, with a third coming when Will Smith holed out to Finn on 30.
Ben Stokes made the first half-century of the match but one run later he was stumped by John Simpson to become the first of three victims for spinner Rayner.
Brief rallies from Mustard (30 not out) and Calum Thorp (23) helped Durham to 168-7 but Finn struck twice as they lost their last three wickets for three runs and set a paltry target for the hosts.
Chris Rushworth struck an early blow for Durham when Sam Robson was pouched by Richardson for only two and Onions accounted for Joe Denly for 32 to increase Middlesex nerves.
But it was an ideal situation for such experienced hands as Adam Voges (36no) and Eoin Morgan (24no) who had added an unbeaten 62 by stumps to take them within sight of an important victory which they will hope will come on Sunday morning.