Ben Duckett capitalised on an early moment of fortune to record an unbeaten century on the opening day of Nottinghamshire's LV= Insurance County Championship match against Middlesex.
Ethan Bamber located Duckett's outside edge when the England opener was still to get off the mark, but the ball sailed between wicketkeeper and first slip and Duckett (119no) was resolute thereafter, bringing up his first hundred of the season to follow on from two fifties in their opener last week.
Middlesex might have been ruing their decision to field first following a 117-run opening stand in just 27.5 overs between Duckett and Haseeb Hameed, who nicked off for 55 as Bamber (2-62) had some overdue reward.
Nottinghamshire then slipped to 152-4 but Duckett was a reassuring presence in the middle, guiding his side to 252-5 when bad light at Lord's brought play to an early end.
Elsewhere in Division One, James Anderson was in the wickets early on at Somerset, though the home side fought back against Lancashire courtesy of unbeaten hundreds from captain Tom Abell and teenager James Rew.
Anderson (2-56) sent openers Sean Dickson (0) and Tom Lammonby (15) back to the pavilion after Lancashire won the toss, with Somerset slipping to 80-4 as 19-year-old Rew walked out to the middle.
Rew - born in January 2004, 13 months after Anderson made his international debut - amassed 114 not out and Abell an unbeaten 119 as Somerset dominated the remainder of the opening day, finishing on 311-4.
Elsewhere, Hampshire closed on 287-4 after being invited to bat first by Northamptonshire at Wantage Road, with Nick Gubbins (125) and James Vince (104no) putting on 198 for the third wicket.
In Canterbury, there were just 42 overs of play possible due to bad light and heavy rain as Essex sit 164-1. Nick Browne (54no) and Tom Westley (71) will resume their unbroken 121-run stand on Friday.
In Division Two, Tom Price had a remarkable day that he won't forget in a hurry, rescuing Gloucestershire from a desperate collapse with his maiden first-class century before then taking a hat-trick on day one against Worcestershire at New Road.
Gloucestershire had stumbled to 45-7 after being inserted, only for Price (109) to stride out to the middle and bash a 98-ball hundred, thumping four sixes and 12 fours before being run out, as the visitors were bowled out for 231.
Worcestershire then slipped from 58 without loss to 59-4, with Price (4-38) having former Pakistan captain Azhar Ali and fellow middle-order batters Jack Haynes and Brett D'Oliveira caught behind off successive deliveries. Price also found the edge of Ed Pollock (34) as Worcestershire closed on 118-7.
Elsewhere, Durham posted 382-6 after losing the toss against Glamorgan at Cardiff, with Michael Jones (69), Scott Borthwick (59), Ollie Robinson (73) and Brydon Carse (53no) all notching half-centuries.
At Hove, Tom Alsop top-scored with 95, while Oli Carter's unbeaten 60 saw Sussex to stumps in a decent position at 275-5 after opting to bat first against Yorkshire.
