Phil Salt and Luke Wells capitalised on their bowlers' earlier work to ensure Sussex finished the first day of their Specsavers County Championship match against Gloucestershire on top.
Sussex paceman Chris Jordan took 3-49 as Gloucestershire were bowled out for 200 inside 78 overs having been put into bat at Bristol.
Their innings was afforded perspective when Philip Salt (53 not out) and Luke Wells (6 not out) safely negotiated 16 overs to usher Sussex to 73 without loss at the close, 127 runs behind with all first-innings wickets in hand.
Second in the table and attempting a return to Division One for the first time since 2005, Gloucestershire were indebted to James Bracey's powers of composure and application on his way to 61 on a pitch which offered encouragement to the bowlers.
A study in concentration, the 22-year-old dominated an opening stand of 48 in 18 overs with Chris Dent, whose search for fluency ended when he followed a Tom Haines away-swinger and was held at slip by Jordan for seven. Gareth Roderick departed soon afterwards, swept up by late swing and comprehensively bowled by David Wiese without scoring.
Bracey stood firm throughout the morning, reaching his fourth Championship 50 of the summer in imperious fashion, pulling Delray Rawlins to mid-wicket for his seventh boundary as Gloucestershire reached lunch handily-placed on 86-2.
In confident mood after scoring an unbeaten hundred at Derby in his last red-ball innings, the Bristol-born batsman clearly had another big score in his sights.
But Sussex had other ideas and staged a spirited fightback in the afternoon sunshine, Jordan initiating the slide with a startling delivery to induce the hitherto faultless Bracey to edge a catch behind.
Tom Smith succumbed to the former England paceman two overs later, fending a rising delivery to slip and departing for a duck. Miles Hammond was next to go for 16, top-edging a pull shot high to square leg as George Garton struck with his second delivery from the Bristol Pavilion End, while Ryan Higgins aimed an extravagant drive at a wide delivery from Wiese and was brilliantly caught by Salt at second slip for 22.
Jordan had Ben Charlesworth caught at the wicket for 28 after tea, Jack Taylor fell in identical fashion to provide Ollie Robinson with a deserved scalp and Matt Taylor was confounded by Will Beer's googly. Only David Payne summoned lower-order defiance, finishing unbeaten on 22 to at least bank a solitary batting bonus point for his side.
Any suggestion that Gloucestershire had under-achieved was afforded further credence when Salt, in assertive mood, took West Indies paceman Shannon Gabriel to task, plundering four successive boundaries in the penultimate over to realise a 56-ball half century as Sussex finished the day in credit.