The September scourge of unreliable weather may yet play a part in determining a County Championship that has the potential to provide another close finish. None of today's matches escaped interruption, with First Division leaders Durham suffering the biggest frustration.
They were restricted to just 31 overs at Derby, allowing Yorkshire to trim three points off their lead by taking nine Sussex wickets at Hove, where bad light limited play to 76 overs.
Yorkshire's position is not as strong as it might have been, however. After winning the toss, they reduced Sussex, who were trounced by Durham last week, to 164 for 7 and it would have been 164 for 8 had Adam Lyth not dropped a regulation chance in the slips, allowing Ben Brown a life on 14.
It proved a costly error. By the close, Brown was 78 not out, having shared an eight-wicket stand of 74 with Steve Magoffin, and Sussex were 276 for 9.
The Durham captain, Paul Collingwood, won the toss and chose to bowl against battling Derbyshire but the home side, who have won three of their last four matches to give themselves a chance of avoiding relegation back to the Second Division, lost only one wicket in scoring 99, as Paul Borrington and Wayne Madsen shared an unbroken stand of 66.
Chris Rushworth produced a full delivery to take out Ben Slater's off stump but Durham's seam attack was unable to exploit conditions effectively, even though the ball swung in the overcast air before rain closed in soon after lunch.
Somerset and Surrey, the sides who began the round in the relegation places, are facing each other at Taunton, where the visitors returned a modest 195 for 8 after choosing to bat first.
Surrey gave a debut to Dominic Sibley, who turned 18 only last week and has been given time off from Whitgift School to play. The England Under-19 opened alongside Rory Burns and though he had made only 10 when he was leg before to Craig Meschede, it was 10 more than Hashim Amla, who returned from short trip home to South Africa to be out for a fifth-ball duck.
Nottinghamshire, themselves not safe, dropped Alex Hales for the second time this season for their trip to Lord's, where Steven Mullaney took his chance at the top of the order, finishing 88 not out against Middlesex.