Set 284 for victory after Essex had declared on 269 for 9, Morris struck 149 to guide Glamorgan to victory and condemn the hosts to fifth place and just pounds 9,000 in prize-money, instead of pounds 30,000 for second place.
Surrey, who also had one eye on dislodging Derbyshire at the start of the day, collapsed to 299 all out and a 124-run defeat against Worcestershire at The Oval to settle for third place and pounds 15,000 after being set 424 to win.
Northamptonshire openers Mal Loye and Richard Montgomerie smashed their way into the county record books to force a draw against Yorkshire at Wantage Road.
Loye hit 28 fours on his way to 205, a maiden double century, while Montgomerie scored 127 as their 372-run stand beat the previous mark set by Norman Oldfield and Vince Broderick set in 1953 against Scotland. Northants finished on 531 for 4, their biggest total in 129 championship meetings with Yorkshire.
Nick Knight and Andy Moles hammered Warwickshire's first century opening partnership of the season to ensure a draw with Lancashire at Edgbaston.
Knight scored 103, his first championship century since May, while Moles struck 59 and with an unbeaten 70 from Trevor Penney, last year's champions finished on 359 or 6.
A battling 63 from Graeme Archer prevented Nottinghamshire slumping to their 10th defeat of the season at Southampton against Hampshire.Reuse content