In a bizarre day’s cricket at Chester-le-Street, with never a dull moment, he almost doubled the total in a last-wicket stand of 164 with Matt Hobden.
Runs continued to flow when Durham’s openers put on 88 inside 16 overs before Robinson completed his outstanding day by having both caught at first slip. Replying to 335, Durham closed on 103 for two.
Robinson and Hobden came together when eight wickets had fallen for 83 runs and made batting look ridiculously easy, just as it had during a second-wicket stand of 88 in 18 overs between Matt Machan and Ed Joyce.
With the ball nipping around after Sussex were inserted on a sunny morning, several of the top order self-destructed as wickets fell regularly in the two hours either side of lunch.
But after going in with Sussex on 145 for seven Robinson looked totally assured and took command after seeing two more wickets go down.
He was joined by Hobden on 171 for nine and the No 11 contributed only three to the 50 stand before he, too, began to play shots.
They took the total to 335 before Robinson edged the second ball after tea to gully to depart for 110, leaving Hebden unbeaten on 65.
Sussex’s previous highest tenth-wicket stand was 156, between G R Cox and H R Butt at Cambridge University in 1908, while the record last-wicket partnership against Durham was 146 between Glen Chapple and Peter Martin at Old Trafford in 1997.
Born in Margate, Robinson came up through the Kent system before Yorkshire took him on in 2013. He is the stepson of England’s assistant coach, Paul Farbrace, who was on Yorkshire’s coaching staff at the time.
Since his release last year he has played for Hampshire and Essex seconds before scoring a century last week for Sussex seconds in a friendly against Middlesex.
The lanky 21-year-old all-rounder was given his chance against Durham because Tymal Mills (back) has joined Lewis Hatchett and James Anyon on the treatment table.
While he obviously likes to get on the front foot, he was skilful enough to drop his hands at the last second and run the ball to third man, where several of his 18 fours came.
The one which took him to 50 off 48 balls was a sliced drive off John Hastings which flew just wide of third slip and he immediately enjoyed another slice of fortune.
He drove the ball back to Hastings, who threw down the stumps and video evidence suggested Robinson was lucky not to be given run out.
At that point Paul Collingwood gambled by bringing on himself and Scott Borthwick, but his attempts to persuade Hobden to sky a leg-side catch resulted in the No 11 pulling him for him for six and four.
With both batsmen now in full cry, Hastings was recalled and tried to bounce them out. A couple of miscued pulls lobbed into space and Hebden fended one delivery just over short leg’s head, but it was all meat and drink to Robinson.
He completed his century off 101 balls by pulling his 17th four off Chris Rushworth, who had enjoyed a spell of three for five in 13 balls in early afternoon.
Cricket’s regulations were made to look silly when tea was delayed because nine wickets were down when the stand was already worth 113.
Hobden, with a total of 50 runs in ten previous first-class innings, also pulled Rushworth for four to reach 50 off 65 balls, then drove his second six.
It was Usman Arshad, who had replaced the injured Paul Coughlin, who finally broke the stand to finish with the best figures of three for 41.
When the last-wicket heroes came on as Sussex’s first and second change bowlers they conceded 50 between them in their first five overs.
But Robinson found some extra bounce to remove Keaton Jennings for 35 and Mark Stoneman for 57.
After his dream debut for Sussex, Oliver Robinson said: “I can’t believe what’s happened. I’m sure I’m not going to have too many days like this.
“I just tried to play nice and straight and keep it simple, but I couldn’t have done it without Matt (Hobden). At first we just wanted to get to 200, then 250 – we had no idea about any record stands. We kept each other going.”
Durham coach Jon Lewis said: They played very well. Perhaps there was a bit of expectation on our part, thinking we had got the job done and the last wicket would come easily, but once they got in it became tricky for us.
“The game hasn’t got away from us. It’s a good pitch and we just need some big partnerships.”