He masterminded one of the great FA Cup final shocks of living memory.
Against the free-spending Manchester City, Roberto Martinez led Wigan Athletic to a highly improbable 1-0 win in 2013.
Through a Ben Watson header, Wigan made the most of a game-plan that had kept City unusually quiet the whole afternoon.
Although Martinez's side would be relegated that season, you would be hard-pushed to find a Wigan fan would would trade away that victory for Premier League survival.
Five years on, Wigan are one point shy of top spot in League One. Managed by former Sligo Rovers boss Paul Cook, they will face Pep Guardiola's Manchester City in the 5th round of the cup on Monday night.
In attendance to watch Keven de Bruyne and Vincent Kompany ahead of this year's World Cup, the Belgian manager Martinez will also be catching up with old friends.
Speaking to The Telegraph, Martinez revealed some of his memories from that incredible day almost five years ago:
It was the first time I remember the chairman Dave Whelan being quite happy just to celebrate.
He always wanted more and more. But after that final, when he came down to the pitch, it was different. He was just so happy ... It was a beautiful moment.
Recalling some of the games leading up to the final however, Martinez discussed a man-management technique that even Alex Ferguson or Brian Clough would be proud of.
Of the man who would become man-of-the-match in the final, Wigan's Callum McManaman was well-known to the Martinez and his coaches as a player who struggled with nerves.
Identifying the moment that he believes enabled McManaman to reach his potential when it counted most, Martinez recalled Wigan's 5th round tie against Huddersfield Town:
So in the week leading up to our fifth round game against Huddersfield [McManaman] trained really well and I knew he expected to play but I told him he wouldn't.
He was surprised and upset but he went to bed, slept well and in the morning I told him, 'You're playing'.
He was man of the match against Huddersfield. From that point on you could see a real difference in Callum and the climax came in that final.
A risky tactic undoubtedly, it certainly paid dividends this time around.
