The next Championship game was a high-scoring draw with Surrey, before keeping up their one-day title challenge with a win over Northamptonshire, taking revenge for their loss in the C&G Trophy.
That was followed up by a seven-wicket win in the Championship over Hampshire, before their luck ran out, and they lost a high-scoring match to Gloucestershire in the National League before saying goodbye to the Twenty20 Cup with a 19-run loss to defending champions Leicestershire.
The match with Sussex was over inside two days and Middlesex were beaten by an innings and 232 runs, the highest margin of defeat suffered by any team in the entire Championship season.
Their seventh Championship draw of the season, against Kent at Lord's, meant that their match with Surrey at The Oval on 21 September looked to be a relegation final, with the loser going down into Division Two.
(BBC scorecard) Middlesex beat Northumberland by 10 wickets to progress to Round Two of the C&G Trophy Rain meant there was no play on the first day at Jesmond.
Middlesex' reply would have been a sorry one but for a big partnership between Owais Shah (83) and Irish left-hander Ed Joyce (70), who continued his great form in the Championship, passing 400 runs in his third match of the season.
With Hampshire losing two quick wickets to be 28 for 2 at the close, the match hung in the balance, with nightwatchman Billy Taylor on 0 and Australian batsman Simon Katich on 1.
Middlesex batted for another 62 overs, allowing Owais Shah to make his century, and Ed Joyce 93, before declaring on 342 for 6, leaving Gloucestershire a theoretical 501 to win.
However, Worcestershire Royals' reply were hampered by wickets falling everywhere, along with lack of responsibility to keep the run-rate up, as Vikram Solanki made 40 off 66 balls and Zander de Bruyn 55 off 74 – too slow to chase 225 in 44 overs.
A burst of wickets followed, which reduced Middlesex to 144 for 5, but a massive cameo from Scott Styris – who scored 71 from 43 balls, including seven sixes – wrested the target up to 244.
In reply, Essex scored quickly enough, but lost many wickets, being 182 for 7 with Ryan ten Doeschate and former England all-rounder Alex Tudor at the crease.
Surrey started slowly, moving to 18 for 1 after 15 overs of quality bowling from Pathan and Alan Richardson, but the stranglehold was eased with Richard Clinton scoring freely as he made his way to 73.
The fourth day was always likely to meander into a draw, and exactly that happened; Surrey were simply unable to take wickets quick enough as the hosts were content to bat to 353 for 6 declared.
Earlier, Australian overseas player Martin Love (111 not out) and Usman Afzaal (122 not out) had occupied the crease for Northamptonshire, sharing a 227-run partnership as the hosts made 283 for 1.
(Cricinfo scorecard) Middlesex (4pts) beat Nottinghamshire (0pts) by 31 runs Middlesex Crusaders used their home batting paradise at Southgate to good effect, smashing Nottinghamshire Outlaws bowlers to all corners as they amassed 314 for 7 in 45 overs – Paul Weekes top-scoring with a run-a-ball 106, while Irishman Ed Joyce pushed the accelerator in the final overs with an 18-ball 41 including six boundaries.
In reply, Nottinghamshire were always going to be in trouble after crashing to 86 for 4, Weekes ripping out two wickets, but Samit Patel and Chris Read lifted them to 231 for 5 before Alan Richardson removed them both.
For Hampshire Hawks, Shane Warne showed somewhat poor captaincy when Zimbabwean all-rounder Sean Ervine was the eighth man to come on to bowl – and then took two for 13 from two overs.
Despite Nic Pothas scoring 59 off 39 balls, the Hawks were nowhere near keeping up with the required pace, and Middlesex bowler Irfan Pathan was a main cause of that – he took three for 16 from four overs, as Hampshire finished on 192 for 7.
Ali Brown made 64 and David Thornely 67 not out as Middlesex Crusaders conceded too many runs at the fine batting track at Lord's, Surrey making 200 for 3.
When Clarke dug out him, Scott Styris and Ed Joyce in quick succession, however, things looked bright for Surrey, and then rain intervened after 11 overs of the Middlesex innings.
Owais Shah kept ploughing on his hard-hitting form, taking James Tredwell to the cleaners in his 59 not out, and Middlesex made it to 145 for 4 with 16 balls remaining in the innings, as none of the opposition bowlers took more than one wicket.
However, it was in vain – with only three wins, they finished fourth in the South Division tables, while Middlesex qualified despite having a poorer net run rate than Hampshire.
His unbeaten 95, along with 27 not out from Luke Parker, saw Warwickshire pass the target with three wickets to spare, despite Middlesex' slow over rate, which caused them to be deducted half a point.
Scott hogged the strike, but couldn't get the necessary boundaries, and Middlesex finished their 45 overs on 198 for 9, five runs short of a victory that would have put them level on points with Essex.
Martin Love and Robert White slashed fifties for an opening partnership of 117, and after two wickets from Chris Peploe, Bilal Shafayat entered.
Taking a fancy to young medium-pacer Chris Wright, the 21-year-old slashed five sixes and seven fours to make 85 not out – only his fourth fifty in List A cricket.
They were put in to bat, and lost wicket-keeper Nic Pothas for 5 early on, but John Crawley and Sean Ervine fought back with a 101-run partnership for the second wicket.
Golwalkar took three wickets on the final day, but it wasn't enough, as Kent made it to 192 for 7 to save the draw – Andrew Hall grinding out 26 in the last 51 minutes with Niall O'Brien before conditions stopped play.
The Lightning fell to 94 for 5, with four Middlesex bowlers getting one wicket each, and despite all-rounder Glen Chapple recording his first one-day half-century of the season with 71, and they were bowled out for 219 an over before the end.
Surrey passed 600 on the third day, before Shah picked up his second wicket of the match, removing Ramprakash for 252 – ending an all-time record fifth-wicket partnership of 318.