Luke Wright scored his second Championship century of the season to put Sussex on top after the opening day of their relegation battle with Northamptonshire at Hove.
Wright strode to the crease with Sussex in trouble of 116-4 after Northants won the toss and elected to make use of a lively wicket.
The England all-rounder put on 50 for the fifth wicket with Ashar Zaidi to steady the ship and then combined with Ben Brown to put Sussex in a position of dominance on 319-6 at the close.
The pair – who made a record stand of 335 earlier in the season – added 136 before Brown was dismissed shortly before stumps for 47.
Wright will resume in the morning on 111 having brought up his 13th first class century off 152 balls with 16 fours and a towering six off Steven Crook.
It is not the first time this season that Wright has completely changed the complexion of a game.
Sussex had done pretty well to lose just the wickets of Chris Nash and Luke Wells in the morning in the face of a testing opening burst from David Willey and Crook on a pitch offering pace and bounce.
Willey softened Nash up by hitting him on the helmet with a ball that reared up off a length with the Sussex opener falling shortly afterwards when he clipped the same bowler straight to short midwicket.
Wells also needed treatment after taking a couple of blows to the body before he was bowled for 26 by Andrew Hall with a delivery that kept a touch low.
Sussex were probably the happier of the two sides at lunch on 87-2 but they lost skipper Ed Joyce and Steff Piolet in the space of seven balls in the afternoon session to give Northants the edge.
Joyce – who had been hit painfully on the chest by Willey – was trapped lbw by the same bowler for 40 with Piolet edging Olly Stone to the keeper for 27 having been dropped in the slips on 18.
Zaidi looked good for his 22 until he suffered a rush of blood in trying to slog James Middlebrook across the line and looped a catch to backward point.
Batting became easier as the ball got soft and Wright and Brown took full advantage. Sussex were 199-5 at tea but they really pushed on in the evening session with Wright being particularly aggressive with anything short and wide.
The new ball brought little joy for Northants with Wright bringing up the 100 partnership by flashing Crook through extra cover for four and then moving into the 90s with a thumping pull off the same bowler which landed in the pavilion.
The crowd applauded loudly when he completed his century but they did not get a chance to clap Brown’s 50 as he edged Hall to slip three short.
James Tredwell ensured the day belonged totally to Sussex by staying with Wright for the remaining five overs and will resume on 14 in the morning.