England captain Joe Root was one of three Yorkshire wickets to fall in the space of 21 deliveries bowled by George Garton as Sussex seized the upper hand on the opening day of their LV= Insurance County Championship fixture.
Yorkshire had reached 60 without loss before both openers were snared in successive overs by left-arm paceman Garton, who also collected the prize scalp of Root, trapped lbw for five after being beaten by some late inward movement.
The trio of wickets swung the pendulum in Sussex's favour as Yorkshire were bundled out for 150 in just 50.5 overs after winning the toss under blue skies at Hove, where the hosts reached 118 for three by stumps.
Sussex also lost their first wicket with 60 on the board, but opener Tom Haines was a reassuring presence at the crease, reaching the close on an unbeaten 71 in front of the onlooking England head coach Chris Silverwood.
Silverwood, handed a broader remit this week of choosing England squads after Ed Smith was stood down from his role as national selector, was joined by chief scout James Taylor to assess the highly-rated Sussex seamer Ollie Robinson, as well as monitor the non-playing Jofra Archer's fitness as he continues his recovery from finger and elbow injuries.
But the pair would have been impressed by the performance of Garton, who has had his own injury problems in recent years but followed up a career-best knock of 97 at Glamorgan with three for 25 from 11 overs against Yorkshire.
Olly Stone and Oliver Hannon-Dalby took four wickets apiece as Warwickshire restricted Essex to 295 at Edgbaston.
Stone was hooked for a rare six by Sir Alastair Cook, who made a swift 46 from 47 balls before nicking off, but the paceman continued his good early season form, including the wicket of England team-mate Dan Lawrence for five.
There were half-centuries for Nick Browne (68), Paul Walter (66) and Ryan ten Doeschate (56) after Essex elected to bat first while Warwickshire reached seven without loss in the four overs before the close.
Tim Murtagh finished with four for 28 while Middlesex colleague Toby Roland-Jones took the important top-order wickets of Mark Stoneman, Ollie Pope and Ben Foakes to restrict London rivals Surrey to 154 all out.
The performances of the seamers vindicated Middlesex's decision to field first at Lord's, and the hosts capitalised on their position as they recovered from 16 for three – Reece Topley doing all the damage – to reach 114 without further loss.
Sam Robson (46 not out) and Robbie White (52no) put on an unbroken 98 after Surrey left-armer Topley had Max Holden caught in the slips before castling both Nick Gubbins and debuting Middlesex captain Peter Handscomb in the same over.
Jake Libby's 117 against former employers Nottinghamshire lifted Worcestershire, who collapsed from 140 without loss to 216 for seven at New Road as they decided to bat first.
However, Ed Barnard (40no) and West Indies bowling all-rounder Alzarri Joseph put on an unbroken 89, a useful eighth-wicket stand as Worcestershire went to the close on 305 for seven.
Lewis Hill top-scored with 68 out of Leicestershire's 233 against Somerset, who would have been satisfied after losing the toss at Grace Road although the visitors closed on 53 for three in reply.
Chris Cooke registered his second century of the season, with his 107 not out helping Glamorgan to 324 for seven against Northamptonshire, who elected to bowl first at Wantage Road.
Ian Holland's 114 and an unbeaten 127 from Tom Alsop steered Hampshire to 292 for three after they guessed right at the toss against Gloucestershire at the Ageas Bowl, while Lancashire reached 260 for seven after being asked to bat against Kent at Canterbury.