Alex Hales scored his first Championship century for nearly two years to put Nottinghamshire in a strong position at Hove.
The England international was unbeaten on 113 as Notts reached tea on the third day on 171-2, leading by 268.
It was Hales’ first century since making 155 not out against Warwickshire in August 2012 and came in quick time as Notts tried to push on in the knowledge that tomorrow’s forecast is not promising.
He reached his 50 off 47 balls and took a further 49 to complete the seventh first class century of his career. Hales went to three figures by cutting Luke Wells for the 16th boundary of his innings and followed it by launching the same bowler over the pavilion for six.
Sussex will be ruing the fact they dropped Hales when he was on 32, Rory Hamilton-Brown putting down a chance at second slip off the bowling of Jimmy Anyon.
Hales put on 128 for the first wicket for Phil Jacques before the Australian opener was dismissed by Chris Nash for 39. Jacques attempted to cut a ball that was too close to him and played on.
The only other success for Sussex during the afternoon session came just before tea when Michael Lumb was superbly caught by Hamilton-Brown at first slip off the bowling of Matt Hobden for 13.
Earlier, Sussex had successfully avoided the follow-on thanks to a partnership of 117 between skipper Ed Joyce and Jon Lewis.
Joyce was unbeaten on 164 as Sussex were finally dismissed for 355, a deficit of 97.