Jake Ball emerged as a potential England prospect, by dismissing Test batsmen Adam Lyth and Joe Root for golden ducks at Trent Bridge.
Ball began day two of Nottinghamshire's Specsavers County Championship Division One match at home to champions Yorkshire by having Lyth lbw.
Sharing the new ball with England star Stuart Broad, he then put himself on a hat-trick when he followed a second wicket - that of another Test player Gary Ballance - by having Root caught low down at slip.
The tall 25-year-old seamer finished with three for 40, either side of a long afternoon stoppage on a day when bad weather took its toll on play at most venues.
But Yorkshire were still able to close on 170 for four in reply to 261 all out, thanks to the resilience of opener Alex Lees (91no).
Liam Livingstone was the star of the show for Lancashire at Taunton, with his maiden first-class hundred in only his second innings.
Livingstone (108no) reached three figures from number seven - adding to the 70 he made in his only previous attempt against Nottinghamshire two weeks ago, taking 139 balls to do so and hitting nine fours and two sixes.
The 22-year-old helped his team turn 295 for four into 493 for nine declared, following the example of his captain Steven Croft (94) as the visitors prospered despite Roelof van der Merwe's three for 87.
Somerset then reached stumps on 14 without loss.
Ben Stokes had to work hard for his four for 117 as Surrey added another 86 to reach 457 all out at The Oval.
Bad weather wiped out much of the final session, but Durham had time to reply with 156 for two after an opening stand of 114 and a half-century each for Keaton Jennings and Mark Stoneman.
Hampshire's last three wickets could add only 21 to the overnight score, and Liam Dawson just two to his 87, in a total of 336 all out against Middlesex in Southampton.
Tim Murtagh bagged a late wicket to finish alongside Toby Roland-Jones with three.
The visitors' reply was on 84 for three when rain brought an early close.
In Division Two, England captain Alastair Cook (130no) and Tom Westley (125) both completed centuries for Essex against Worcestershire at New Road.
England Lion Westley got there first, before the rain break, with 17 fours and a six from 163 balls in a second-wicket stand of 222.
Then Cook followed, with 15 fours and a rare maximum too from 206 balls for his third championship hundred of the summer already, as early pace-setters Essex kept up their good work to close on 335 for two.
Leicestershire also continued their fine start to the season, and Paul Horton (100) his for a new club by making his first century for the Foxes.
The opener reached three figures with 14 fours from 167 balls, against Sussex at Hove, sharing a stand of 114 with captain Mark Cosgrove (80) as Leicestershire moved into a commanding lead of 137 with power to add on 300 for four at stumps.
Opener Daniel Bell-Drummond (84) has also begun the summer very well, and was top-scorer for Kent as five batsmen passed 50 in their 488 all out at Canterbury - where seamers Michael Hogan and Craig Meschede shared seven wickets.
Glamorgan, 228 adrift on first innings, then reached stumps in more trouble on 16 for one.
At Northampton, Shiv Thakor finished unbeaten on 83 out of Derbyshire's 324 all out - home seamers Rory Kleinveldt and Azharullah sharing seven wickets.
Northamptonshire then reached a promising 66 for none before the rain arrived.