England bowler Ollie Robinson stole the show with a seven-wicket haul against Worcestershire on a day where Sussex team-mate Steve Smith was forced to wait before he made his LV= Insurance County Championship bow with the bat.
All eyes were on Australian great Smith at New Road in the first of three games for Sussex ahead of this summer's Ashes series, but away captain Cheteshwar Pujara decided to field first after he won the toss on Thursday.
It proved a wise decision with England seamer Robinson ripping through the Worcestershire top-order on his way to figures of 7-59 in a pleasing sign for the hosts' chances of winning back the Urn in July.
Worcestershire did stage a recovery from 44-5 to eventually make 264 thanks to half-centuries from Adam Hose (59), Matthew Waite (59) and Joe Leach (53), but there was still enough time left for Sussex to bat on day one of the Division Two encounter.
Smith stayed in the pavilion though with opener Ali Orr and number three Tom Alsop able to get the away side through to the close on 63-1 with the Aussie set to bat at number five on day two.
Jonny Bairstow took a positive step in his bid to prove his fitness for the Ashes by claiming three catches for Yorkshire against Glamorgan.
Bairstow, fit again after an unfortunate leg break last summer, kept wicket at Headingley and produced a superb grab down the leg-side to dismiss Kiran Carlson.
Glamorgan were all out for 245 and indebted to another Australian with Marnus Labuschagne top-scoring with 65 before Yorkshire suffered a late collapse to finish on 62-5 with Bairstow not out on two.
Elsewhere in the second tier, Leicestershire were skittled for 122 with Derbyshire's Henry Brookes claiming 6-20, which included the scalp of England all-rounder Rehan Ahmed for 23.
Hosts Derbyshire managed to wipe out the deficit before bad light brought proceedings to an early end with Haider Ali scoring 54 to lead them to 144-3.
Both Stuart Broad and James Anderson were overshadowed by Brett Hutton at Trent Bridge on a good day for Nottinghamshire opener Haseeb Hameed against his old club Lancashire in Division One.
England seamer Broad picked up two wickets and Olly Stone also claimed a brace as Lancashire were all out for 214 but it was Hutton who did the majority of the damage for the home side with 5-66.
Lancashire, largely through Tom Bailey with 48 not out from 29 balls, had scored at almost five an over and it allowed Anderson time to get stuck into Nottinghamshire on the first day but Hameed came through unscathed to close on an unbeaten 57.
While Anderson finished wicketless from his seven overs, his team-mates fared better to reduce the hosts to 119-5 on a good day for bowlers at Trent Bridge.
Chris Woakes caught the eye for Warwickshire at the Ageas Bowl to dismiss Hampshire for 229.
Woakes picked up three scalps but Hampshire captain James Vince stood firm with 75 not out before Warwickshire reached 82 without loss at the close with Alex Davies unbeaten on 46.
Essex saw Alastair Cook (51), Tom Westley (62) and Matt Critchley (60) all pass 50 against Surrey but Gus Atkinson's 6-68 along with Will Jacks' two-fer saw them all out for 314 at Chelmsford.
Rain badly affected the other Division One match at Taunton where Northamptonshire closed on 137-4 thanks to Ricardo Vasconcelos' 70 against Somerset on a day where only 37.4 overs were possible.
