Everything was going well for Sussex until the seventh over, when Steve Magoffin prepared to celebrate his 35th wicket of the season and hail Ed Joyce's decision to put Middlesex in as Chris Rogers, on three, edged the ball towards second slip and the safe hands of Mike Yardy.
On this occasion, Yardy's reliability deserted him. Seven hours later, as the Sussex bowlers wandered wearily towards the pavilion, Rogers was just a few steps behind, bat tucked under his arm, having advanced his score to 161 not out.
Rogers was dropped on 105 as well, when he tried to cut a wide ball from Will Beer and made rather a mess of it. Chris Jordan dived to his left at slip but was no more successful than Yardy had been. One miss was excusable, you might say; two really was careless. An Australian with his sights on an Ashes comeback is not a man to whom chances should be offered so casually.
Especially one in the kind of form the Middlesex captain is enjoying. Rogers had a double hundred against Surrey and four other half-centuries this season before this match and reaching 148 in this innings took him to 700 runs in the Championship.
Supported first by Sam Robson, the Australian who wants to play for England, and later by Neil Dexter, with both of whom he shared century partnerships, Rogers put Middlesex in control and reinforced the notion this year's title race will be close. Sussex, who omitted Rory Hamilton-Brown, arrived as leaders, eight points ahead of Yorkshire and 10 in front of Middlesex, but those three make up only half the contenders.
Joyce's decision to field stirred Sussex's social networkers into some predictable tut-tutting but in his defence he has at his disposal the most potent strike bowlers of the season so far and even with James Anyon rested and Monty Panesar injured he had reason to hope for better. You could not accuse him, either, of not knowing local conditions, having spent nine years here. And had that first chance stuck, it might have been a different story.
In the event, neither Magoffin nor Jordan added to the 68 wickets they have between them. The only inroads were made by the spinners, Beer and Chris Nash.
Beer, the wrist spinner, pushed one through to trap Robson on the back foot with the last ball of the morning and bowled Joe Denly between bat and pad with a ball that skidded straight on. Nash's off-spin accounted for Adam London.