Gloucestershire 210 (Dent 66, Cartwright 4-33) and 66 for 2 trail Middlesex 455 for 8 dec (Gubbins 99, Malan 76, Morgan 76) by 179 runs
Gloucestershire face an uphill battle to stave off County Championship defeat on Monday after they were made to follow on against Middlesex at Lord's. Visiting captain Chris Dent, who had struggled for form with the bat, top scored with 66 but it was not enough to prevent his side being bowled out for 210 in two sessions.
Middlesex's Australian allrounder Hilton Cartwright returned career-best figures of 4 for 33 in the first innings, with Tom Helm taking 3 for 48. That left Gloucestershire 245 behind at the start of their second innings and, although the West Country side reduced the deficit by 66, they go into the final day with just eight wickets standing.
Middlesex bowled well in the morning but initially without any reward as both Dent and James Bracey found the gap between slips and gully all too frequently. Dent - who averaged just 8.5 coming into this match - survived what looked a strong lbw shout from Steven Finn, while Sam Robson spilled an edge from Bracey at first slip.
The opening pair put together a stand of 72 before Cartwright made the breakthrough, persuading Bracey to attempt a cut that saw him caught behind off the bottom edge.
Gareth Roderick lasted just four balls, falling leg before to Cartwright for a duck, and Ollie Rayner reduced the visitors to 90 for 3 when his first delivery accounted for Graeme van Buuren. Jack Taylor struck a breezy 22 before Finn pinned him lbw in the fifth over after lunch - and Helm then took centre stage with a three-wicket burst to drive home Middlesex's advantage.
Helm's spell of 3 for 16 included the scalp of Dent, who was caught prodding outside the off stump, and a simple return catch to remove former Middlesex allrounder Ryan Higgins.
Benny Howell, who came in down the order after a stomach upset had kept him off the field the previous afternoon, showed some resistance with a gritty knock of 47 from 87 balls. But Cartwright's second spell earned him the wickets of Craig Miles and Daniel Worrall and he finished off the innings just before tea, taking a skier at mid-on to remove Howell.
With Middlesex skipper Dawid Malan enforcing the follow-on, Howell was soon back at the crease alongside Dent and the pair made a solid start to their second innings. Malan rotated his bowlers without success until Howell lost his wicket for the second time in less than two hours, chopping James Harris on to his stumps.
Harris was unlucky not to pick up Dent as well, within Rayner putting down a chance at second slip - but the Gloucestershire captain departed soon afterwards for 35 as Helm found his outside edge.