The two teams produced a classic as Leeds were ahead three times before being beaten by a 102nd minute Newcastle winner scored by Harvey Barnes.
The loss ends a run of seven unbeaten games for the visitors and Ampadu reflected afterwards: “The dressing room is very disappointed, as it rightly should be.
“We have been on a good run and building this momentum and we thought we could do that again today.
“There are so many parts that were good, scoring three goals. It was a good effort of wanting to get the fourth goal and bombing forward but just maybe that little bit of naivete to manage the game out, obviously it is going to be difficult when they are putting on so much pressure. We just didn’t see out of the game.
“There are so many bits that we could do better from. The Premier League has fine margins and we came out on the wrong side of it today.
“I think maybe after we have scored every goal, we can be a little bit harder to break down in that first couple of minutes. So, there are definitely some lessons learned.
“There is still such a long way to go in the season. No one is safe from relegation yet and that is our mentality. We have to keep fighting, to keep building.”