Sussex 439 for 5 (Salt 130, Haines 124, Finch 56, Brown 50*) v Durham

John Arlott said luck was often nothing more than opportunity. In the cool of this unforgettable evening Tom Haines might admit the old boy had a point. For it was only on Tuesday, when Chris Jordan was called into the England Lions squad, that 19-year-old Haines was told he would be playing his third County Championship match for Sussex and his first for nearly two years. He had scored 12 runs in the previous three innings and may have been preferred to Laurie Evans because he bowls a bit of seam up. He needed his mum to give him a lift to Arundel from the second-team match at New Malden.

So there was no sight more glorious on an afternoon littered with blessings than to see Haines' eruption of joy when he reached his maiden century with a leg glance off Nathan Rimmington. It was the 19th four of an innings brimming with all the bravery of youth and none of its diffidence. To their credit Durham's players applauded the landmark but their reaction was pardonably overshadowed by the cheering of the Sussex supporters beneath the horse chestnut or the joy of Haines' team mates, almost all of whom were enjoying the shade of a blue gazebo alongside the fans.

Yet Haines' achievement was merely the half of it. Three overs previously 21-year-old Phil Salt had also notched his first hundred when he pushed a single off Will Smith. Compared to Haines, Salt is a grizzled old pro; this is his 13th first-class game. But he is also a trifle more naturally aggressive, a trait made plain by his succession of on-drives and by his early pull for six into the marquee nearest the chestnut.

Yes, this was an afternoon of tents and trees and an occasion recognisable to Sussex supporters raised on the Langridges and the Parkses. Two mobile phones were handed in but it was never made clear whether their owners had accidentally lost them or deliberately renounced modernity. In the morning Durham even bowled 31 overs, just one short of the notional target for the session.

Unfortunately for Paul Collingwood and his bowlers it was their only achievement of the session after Matt Salisbury's dismissal of Luke Wells. For the rest of the morning and much of the afternoon the cricket was dominated by the Salt's square drives and Haines' clips off his toes.

"Grey day for the show," wrote Philip Larkin in his warm evocation of Bellingham's annual pastoral and perhaps it was Arundel's morning cloud on the first morning which persuaded Collingwood to bowl first. Either way, his seamers could not justify his decision in the morning session and by mid-afternoon a powerful sun was coaxing spectators to the bars and refreshment vans.

On a day when Durham's bowlers needed chances to go to hand, they instead saw them fall beyond or over fielders. When he was only 36 Haines edged Rimmington a foot or so past a diving Will Smith at slip; in the same bowler's next over he dishclothed a pull just over Josh Coughlin's head at mid-on; when he had made 27 Salt nearly played on but booted the ball just past the stumps; and shortly before reaching his century he lofted Smith down the ground and saw the ball land just beyond a flailing Salisbury.

Haines and Salt had put on 244 and set a new second-wicket record for matches between these counties when they departed either side of tea. Having made 124 off 167 balls, Haines nicked Cameron Steel to Collingwood at slip; in the first over after the resumption, Salt top-edged a slash off Salisbury to Gareth Harte at third man and departed for 130.

Sussex supporters spent the rest of the evening enjoying Luke Wright's 32, Harry Finch's half-century and Ben Brown's unbeaten fifty. But that trio know their innings will be footnotes to the day. Durham's followers, again following their team in good numbers, could be consoled by Salisbury's three wickets. But spectators of any stripe will remember the time they saw two freshman cricketers take their chance on the big stage in a small corner of England. "Luck," Sussex folk may say when reminded of that Arlott quote, "Luck was being here to see it."

Paul Edwards is a freelance cricket writer. He has written for the Times, ESPNcricinfo, Wisden, Southport Visiter and other publications