Middlesex lost four wickets in the final session after Kent's batsmen had piled up the records at Uxbridge.

At 109 for four, in reply to a mammoth 652 for seven declared, Middlesex are already staring at defeat against the LV Division Two leaders - with two days still to go.

Darren Stevens, resuming on 129 in Kent's overnight 390 for four, equalled his career-best score of 208 - and Justin Kemp remained unbeaten on 138 when the declaration finally came at 2.30pm on the second afternoon.

Middlesex openers Nick Compton and Adam London got through to the interval, but afterwards it did not take long for Kent to exert a stranglehold on the match.

In the second over after tea, the left-handed London was lbw to James Tredwell's arm ball, giving the off spinner his 61st county championship victim of a prolific season that has put him back into England winter tour contention. Eighteen months ago, Tredwell was a member of England's one-day squad in New Zealand but has not figured since.

Compton was then bowled off stump, playing down the wrong line to Azhar Mahmood - and Tredwell struck again with a quicker ball that also went on with the arm to pin Dawid Malan, another left-hander, in front.

Kent's decimation of the inexperienced Middlesex top order - the average age of their top six is just 22 - continued in the next over when Azhar won another lbw appeal against Dan Housego.

Neil Dexter and John Simpson did manage to see things through to the close, but Middlesex face an apparently hopeless task of saving the game - especially as the dusting pitch, though still slow and flat, is starting to take some turn.

Stevens and Kemp's partnership of 228 in 48 overs is a new Kent fifth-wicket record against Middlesex - beating the 169 posted by Brian Luckhurst and Asif Iqbal at Canterbury in 1971.

Stevens had batted for 255 balls and hit 34 fours when he chopped on trying to cut Malan. His previous score of 208 was against Glamorgan at Canterbury in 2005.

Kemp reached his second hundred of the season with a six pulled off Malan into the car park beyond midwicket, but otherwise he was happy enough merely to accumulate remorselessly - going to 50 from 70 balls and taking another 71 to reach three figures.

In all, Kemp faced 201 balls and struck 15 fours - and there was also a big six over long-on by Azhar, off Malan too, before Rob Key's declaration changed the nature of the game from free-scoring strokeplay to backs-to-the-wall defence.

Kent's total, meanwhile, is their highest against Middlesex in first-class matches and also the highest first-class score made on this Park Road ground.