A last-minute win over Benetton Treviso, a first-ever Heineken Cup try, a Heineken man-of-the-match award and a greeting which continued into the evening were the personal highlights of the trip to northern Italy for the tighthead prop.
Castrogiovanni posed for photos and signed autographs for both sets of supporters for more than an hour after the final whistle, as well as being the main attraction for the Italian media.
But the Tigers prop admitted: “I’m very relieved we won. It was really close. I don’t think we played our best and when that happens you can lose the game.
“They played really well, they kept going forward, they have a massive defence and they’re good at the lineout and scrum.”
Castrogiovanni’s first try in 43 Heineken Cup matches shortly after half-time gave Tigers a valuable 20-16 lead, but the English champions had to come from behind again to clinch a 34-29 victory in Round One.
“With the new rules you need to keep control of the ball and the referee will look after you,” he said. “We threw too many fancy passes, and there were too many knock-ons and passes on the floor. Treviso kept the ball and looked after it.
“But we got five tries and five points and that is the job we have come for. Now we can go home, look at our mistakes and try to get better.”
The Scarlets from Wales are next up to Tigers as they return to Welford Road on Sunday (3pm). Tickets are available now via the Tigers ticket office. Book online, phone the Tigers ticket hotline on 0844 856 1880 or call in at Welford Road.