Conor Murray says captain Rory Best dragged Ireland through the closing stages of their hard-fought win over Australia in Dublin.
Best was making his 100th Ireland appearance and typically led by example in the 27-24 victory, which saw Ireland defeat South Africa, New Zealand and Australia in a calendar year for the first time.
The hosts led by 17 points at one stage and were made to work hard to get over the line, with Murray crediting Best - just the fifth Irishman to reach a century of appearances for his country - with playing a key role.
"[That was] unbelievable," he told Irish Rugby TV. "Just to give it to Rory, it was great that we got a win for him.
"No-one deserves it more. He's a very, very liked character around the squad and everyone respects him.
"He probably dragged us through the last 20, maybe even the last half an hour, because it was very difficult - we were chasing shadows there for a little while.
"This team has a lot of heart. It's unbelievable to play for this team at the moment, and we have a great buzz around the squad."
Team-mate Andrew Trimble believes Ireland's historic treble against the southern hemisphere giants shows the team's potential.
"This is a side, I think, that has a lot of potential and can do big things," he said.
"It's great that we've got a big opportunity going into the Six Nations in February. We can take a few people on and be confident in what we can achieve.
"We've done it here, we've done it against the world's best, and it's exciting to be a part of this."