Worcestershire 383 (Cox 61, Ferguson 56, Wessels 55, Leach 54*, Robinson 5-84) and 82 for 2 drew with Sussex 255 (Brown 80, Jordan 52) and 424 (Evans 113, Thomason 90, Brown 64)
Released by Warwickshire less than two weeks ago, Aaron Thomason has wasted no time in suggesting that his former employers might regret allowing a player on their books since he was was 12 to join another county without perhaps seeing the best of him.
Thomason, who will be 22 next week and signed for Sussex days after his release largely to answer a bowling crisis, marked his debut with a match-saving performance with the bat as Worcestershire's hopes that their unscheduled visit to Chester Road might reignite their promotion challenge came to nothing.
The bustling seamer and T20 big-hitter played an innings of considerable composure to make 90 batting at No. 10, guiding his team from 314 for 8 to 424 on the final day, effectively putting victory out of reach for the home side, who had felt there was an opportunity after Sussex had resumed five down and only 108 in front.
Although he was missed on two, his error in offering a difficult chance down the leg side behind the stumps made his achievement no less impressive. After Ollie Robinson had been ninth man out at 324, slapping a short, wide ball from Ed Barnard straight into the hands of backward point, Thomason saw to it that his final partner, Abidine Sakande, something of a No. 11 in the traditional sense, faced only 26 balls in 78 minutes as Worcestershire strove for the final wicket.
At the same time as cleverly protecting the strike, he wasted few opportunities to push along the scoring, making sure that Worcestershire's potential target became steadily larger. As well as 11 fours, he plundered four sixes, all driven hard down the ground, one each off the pace of Barnard and Adam Finch, two off Daryl Mitchell.
It was a frustration that he could not make his day even more memorable, bowled in an attempted sweep against Brett D'Oliveira's leg spin. Nonetheless, as first-class debuts go, despite failing to take a wicket and not fielding with particular distinction, it was one with which he could feel pretty pleased.
"I was gutted not to get the hundred, to be honest," he said. "But you win some, you lose some. I'm really pleased with what I did today and I just need to find that consistency moving forward.
"Coming here gives me a fresh start. I had been with Warwickshire since I was a boy and it was a case of getting out of my bubble, really.
"It is a new beginning a long way from Birmingham. They are a good bunch of lads and I'm excited about what is to come in the future.
"I wanted to play all formats and I've played a lot of white-ball cricket up to now. It just shows the depth Sussex have in their batting that I was coming in at 10. Without being boastful, I consider myself a proper all-rounder and I'd be happy to bat as high as four or five."
Sussex moved for Thomason after injuries to George Garton and Pakistan pace bowler Mir Hamza compounded the loss of Jofra Archer to England.
Jason Gillespie, the south coast county's head coach, said: "What we like about Aaron is that he bowls briskly, medium pace and he swings the ball away from right-handers consistently and although he is not express pace he has a bit about him as a character.
"He showed a lot of promise without bowling a lot and the way he batted, the situation management he showed in protecting the strike was excellent. I apologised to him for batting so low because he is a better player than that.
"He scored a lot of second-team hundreds for Warwickshire and I see him moving up the order pretty quickly. I thought his innings today was very mature for someone of his age, he was very impressive."
The chance he gave off Ed Barnard's bowling was a difficult one for the wicketkeeper but the way Ben Cox thumped his first on the ground after getting a good glove to it suggests it was one that might have been taken on another day.
Thomason took full advantage, and by the time he was out Sussex had stretched their lead to 296, which made the draw inevitable with only forty overs left in the game.
Worcestershire mainly rued the loss of Wayne Parnell on the third day, the South African's withdrawal with an injured hamstring crucial in allowing Sussex to recover from 34 for 4. Parnell is likely to be absent for at least a couple of weeks.
Avoiding defeat was important for Sussex, who occupy the third promotion spot in Division Two on 93 points, some 18 points ahead of fourth-placed Derbyshire. On 71 points in sixth position, with a game in hand, Worcestershire remain handily placed with still half the season to go.
Meanwhile, Warwickshire have agreed a one-month loan deal with Lancashire for left-arm seamer Toby Lester.
Lester has played 11 first-class matches and 11 T20s, taking 12 and 15 wickets respectively. He will be available for the Division One Championship match against Surrey starting at The Oval on Sunday.
Warwickshire suffered further injury blows this week with confirmation that fast bowler Ryan Sidebottom is out for the rest of the season with a stress fracture to his right shoulder blade. Liam Norwell will undergo a scan on the left hamstring injury sustained in the win against Yorkshire this week and George Panayi will under have a scan on his rib problem. Henry Brookes has a ligament tear in his hip and will be out for at least a next week.