Warwickshire fought back with the second new ball at Horsham after Craig Cachopa and Luke Wright had put firmly on top on the opening day of their Championship.
Wright and Cachopa put on 174 for the fourth wicket to guide Sussex to 294-3 before Warwickshire claimed four wickets for just 19 runs near the end.
Sussex had been on top for the majority of the day but those late breakthroughs brought Warwickshire right back into the contest with the score 314-7 at the close.
It was quite a turnaround after Cachopa and Wright had completely dominated since coming together with the score 120-3 soon after lunch.
Sussex had lost only lost Luke Wells in the morning session after winning the toss when the opener was superbly caught behind by Tim Ambrose for 35 off the bowling of Rikki Clarke.
But from 99-1 at lunch they found themselves in a spot of bother as Joyce was bowled on the drive by Keith Barker and then Nash was trapped lbw by the same bowler having made his third half century of the season.
Cachopa was given a reprieve on 27 when he was dropped behind the stumps by Ambrose off the bowling of Patel and took full advantage.
He reached his maiden Championship half century from 89 balls while Wright got there a few balls earlier from 72 deliveries.
The pair took Sussex to tea at 230-3 and had extended their partnership to 172 when Warwickshire took the new ball after 80 overs.
It did the trick as Cachopa fell for 84 as he edged a ball from the previously disappointing Chris Woakes to Clarke at second slip.
Wright fell 11 runs short of what would have been a third century in five innings when he chased a wide ball from Barker and edged behind.
Steffan Piolet followed in bizarre fashion as he stepped on his stumps trying to turn a short ball from Woakes to third man.
Boyd Rankin then picked up the wicket of Chris Jordan as the England man bottom edged a pull onto his own stumps.