Nottinghamshire, Warwickshire, Sussex, Essex and Gloucestershire all harbour hopes of sealing a semi-final spot as the Clydesdale Bank 40 enters its final round of group matches on Saturday.
Nottinghamshire crashed to defeat at Durham but still hold a sizeable lead at the top of the LV= County Championship with two games to play. Ben Harmison's three wickets in four balls were key.
Jimmy Adams hit a brilliant, defiant 194 but relegation-threatened Hampshire failed to stave off defeat in a thrilling LV= County Championship clash with Lancashire that went to the final over.
Chelmsford will host the Second XI Trophy final between Essex and Lancashire on Monday September 13, the ECB has confirmed.
Pakistan overcame setbacks on and off the field to beat Somerset by eight runs in their limited-overs warm-up match in Taunton, though Zander de Bruyn's unbeaten 122 challenged them all the way.
Ravi Bopara and Grant Flower hit half-centuries as Essex comfortably beat Middlesex by seven wickets at Chelmsford to keep alive their hopes of reaching the Clydesdale Bank 40 semi-finals.
LV= County Champions-elect Nottinghamshire face an intriguing final day, with Durham leading by 308 runs with five wickets standing following Gordon Muchall's timely second century of the season.
Hampshire, led by Jimmy Adams' second successive century, are making Lancashire fight hard to wrap up victory going into the final day in the LV= County Championship match at Liverpool.
Chris Woakes completed a brilliant all-round display as Warwickshire saw off relegation rivals Kent inside three days in a vital LV= County Championship Division One clash at Edgbaston.