Jose Mourinho has finally revealed what he whispered to Pep Guardiola after Thiago Motta had been sent off in Inter Milan’s famous Champions League semi-final clash with Barcelona.

The two managerial powerhouses faced off at the peak of their powers back in 2010, with Barca’s incredible team looking to become the first side to retain the Champions League. But they were stunned by Inter in the first leg at San Siro, losing 3-1 with Wesley Sneijder and Diego Milito in sensational form, and Mourinho served up arguably the greatest defensive masterclass of his career in the return leg at Camp Nou.

Although Gerard Pique scored late on, the Italian side kept a rampant Barca side at bay for the majority of the match despite having to play with 10 men after Thiago Motta was sent off inside the first half-hour.

Sergio Busquets rather conned the referee into showing a red, famously peering out from behind his hands as he rolled around on the floor, with Mourinho seething with the decision. One of the many iconic images from that classic match saw Mourinho approach Guardiola on the touchline seconds after the dismissal as he gave tactical advice to Zlatan Ibrahimovic, listening in to the conversation before whispering something in his ear.

The self-proclaimed ‘Special One’ has now revealed what he told his managerial adversary in that exchange, claiming the Barca dugout reacted as though they had already won the game. In an interview with Italian newspaper Gazzetta a decade on from that famous night in Catalonia, Mourinho said: ‘In the stands you have time to experience the drama, at the limit you can pray, but on the field you have to find solutions.

‘I said it was the most wonderful defeat of my career: we didn’t lose 1-0 but we won 3-2 in epic conditions. ‘When Busquets fell I was diagonally between our bench, theirs and the point where Thiago Motta was sent off. Out of the corner of my eye I saw the Barcelona bench celebrating as if they had already won. ‘Guardiola called Ibra to talk tactics – tactics in 11 against 10! I just told him: “Don’t start the party yet, this game is not over.”’

Guardiola was rather critical of Inter’s approach to the match afterwards, with Mourinho parking his proverbial bus for 90 minutes, though he says he would have been more attacking – just as they were in the first leg – but for a last-minute injury. He added: ‘We earned the right to play against them how we wanted. Also, if [Goran] Pandev had not been injured in the warm-up, we would have played with him, Sneijder, Eto’o and Milito.