Dupuy grabbed a last-minute try as Tigers secured a 20-15 victory which earned a semi-final against Cardiff Blues at the Millennium Stadium on Sunday, May 3.
The French scrum-half, on as a 50th-minute replacement for Harry Ellis, ran in from 20 metres to score under the posts.
“I wanted to pass but nobody was there, I saw the defence go to Sam Vesty and Geordan Murphy, and leave me a big space,” he said.
“I had not seen the clock, but after a lot of players came to me I realised it was 79 minutes and it was good for us.
“The supporters pushed us a lot, it was a very hard game.”
Dupuy, who was a member of the Biarritz squad that went all the way to the Heineken Cup Final in 2006, can now look forward to a last-four showdown with Cardiff Blues.
“There will be a lot of supporters and there will be a good atmosphere,” he said. “But first we need to continue to play well against Saracens and Bristol, then think about the semi-final.”
