The Posh co-owner said the 26-year-old proved exactly why he was top of manager Grant McCann’s wanted list this summer following his second-half performance against Cheltenham on Saturday.
Introduced at half-time at Whaddon Road alongside Joe Ward – who was linked with the Blues this week – the former Fratton favourite helped the League One new-boys come back from 2-0 down to record a 3-2 win.
That earned him praise from MacAnthony, who admitted he could finally see why Thompson was so highly-rated by McCann following the expiry of his short-term deal at Gillingham.
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The former Millwall midfielder subsequently joined Peterborough on a free transfer soon after his Priestfield exit.
That ended prolonged hopes of a return to Fratton Park, where he endeared himself to Pompey fans over the first half of the 2018-19 season.
Although, Blues supporters began to move on after seeing Thompson for the first time since when the Blues took on the Gills during the second half of last term.
Yet MacAnthony is now in no doubt that Peterborough have brought in a player of quality.
Speaking on his The Hard Truth podcast, the Posh chairmain said: ‘To be fair, and I’m going to give the gaffer massive credit, Ben Thompson was an absolute revelation.
‘Forget about Wardy, who came on, 50-per-cent fit, created two goals, got out wide, got the ball in the box, three goals.
‘But for me, one of the big differences was Ben Thompson – who came in there next to Marrio (Jack Marriott) – and he was proper Ben Thompson.
‘The manager really wanted him – now I can see why.
‘I mean, the boy was just all action.
‘He’ll probably be the first to admit he’s not technically the best in the world but forget that, it’s the other stuff that he does that’s even more impressive.
‘He just ran his guts out in that midfield.’