After cancelling a practice session on Monday, Williams arrived at the Devonshire Park practice courts at about 14:30 BST and word quickly spread around the grounds about what was going on.
In a far corner of the site, Williams put on her tennis shoes and stepped on to a court in the shadow of Eastbourne’s theatre hub.
The stage was set – for the rehearsal, at least.
Hordes of long lenses pointed in the direction of Williams. Tons of camera phones were pressed up against the net separating the court from the watching fans.
Jabeur, who said earlier in the week she “didn’t know” why Williams had picked to play with her, turned up shortly after.
The pair had previously “talked a little bit”, added the world singles number three, but “never really about tennis”.
After exchanging a warm handshake and even warmer smiles, the pair limbered up with a gentle knock, practised some volleys and hit some serves before teaming up on the same side of the net for the first time.
The chemistry started to build as they played some points against Williams’ coach Eric Hechtman and hitting partner Jarmere Jenkins.
When the curtain raised for real on Eastbourne’s centre court, the pair also grew in cohesion and confidence.
On why she chose Jabeur, Williams said: “When we saw her name in, it was immediately like, OK, she would be great to play with.
“I love her game, I love her style of play. She has a great volley, clearly has a great drop shot and she has been having a phenomenal couple of years.
“It just made a lot of sense, it was a good solution for me.”
The crowd in Eastbourne certainly agreed. Hundreds stayed until the end of a match that finished at 20:27 local time on a summer evening which had turned chillier as the match progressed
“That was certainly worth hanging on for,” said one ecstatic female fan in front of the media seats. “What a night.”
She wasn’t the only fan pleased with her day out.
As Williams left the practice court, heading back to the Winter Garden which is usually used for cabaret events and conferences, she signed some autographs for a lucky few.