Donald returned Warwickshire's competition-best figures of 6 for 15 as Yorkshire were dismissed for 56 - their lowest score in 27 seasons of Sunday League cricket.
"Every time I play against them I seem to take wickets," Donald said. "It's not something that I can explain, but I'm very pleased with the way I'm bowling at the moment."
The beleaguered Derbyshire captain Kim Barnett made light of difficult conditions at Chester-le-Street to help his side to a five-wicket victory against Durham.
Derbyshire had slipped below their hosts to the foot of the County Championship the previous day. But the pitch held no fears for Barnett, who always looked comfortable as he contributed 38 to a fourth-wicket stand of 62 with Daryll Cullinan.
Barnett was finally caught at the wicket off Manoj Prabhakar. Cullinan hit five fours in his 91-ball half-century and remained unbeaten on 52 as Derbyshire reached 114 for 5 to win.
The Sunday League leaders, Glamorgan, inflicted a nine- wicket defeat on Surrey at The Oval. Glamorgan took just 20.1 overs to seal victory, with Steve James hitting an unbeaten 80 after taking just 37 balls to reach his half-century. The leaders overcame the loss of their skipper, Hugh Morris, who contributed 14 to a 74-run opening stand in less than 10 overs, to romp to their victory target of 153 in 81 minutes.
Paul Johnson dealt a severe blow to Kent's title hopes at Trent Bridge. Johnson hit 15 fours in his unbeaten 104 to steer Nottinghamshire to a nine-wicket win with 33 balls to spare.
Kent faced an uphill task, chasing 195 for 1 after a disastrous start in which they were reduced to 38 for 4 after six overs and then slipped to 91 for 6.
Nigel Briers and Paul Nixon shared a record-breaking opening stand to pave the way for Leicestershire's 41-run victory over Northamptonshire at Northampton. The pair put on 144 in 25 overs to beat the county's previous highest first-wicket partnership in the competition, 140 between Briers and David Gower against Derbyshire in 1982.
Leicestershire finished with 246 for 5. Northamptonshire could manage only 205 for 7.
Jason Lewry bowled Sussex to a 16-run victory over Somerset at Bath. The left-arm medium pacer claimed 4 for 29 as the home side, replying to Sussex's 197 for 8, were bowled out for 181 in 39.1 overs.
Worcestershire's new captain, Tom Moody, hit an aggressive 108 but could not force victory against Hampshire at Southampton, where the match ended in a tie with 275 runs apiece. In a last over bowled by Heath Streak, Worcestershire needed nine to win. Phil Newport took five from the first two balls, Vikram Solanki took two from the third but was then caught on the third man boundary by Martin Thursfield. Two runs were needed from the last ball but Newport could manage only a single.Reuse content