Hailing the Portuguese superstar as "a genius" as he gave his verdict on his latest hat-trick that fired Real Madrid to a Champions League quarter-final win against Bayern Munich on Tuesday night, Keane didn't hold back as he poured praise on the 32-year-old forward.
Ronaldo put Madrid level at 2-2 on the night in the first period of extra time when he scored his 100th Champions League goal, from a clearly offside position, before he wrapped up his treble with another disputed goal and Marco Asensio added a fourth.
The Bundesliga leaders were angered by several key decisions by Hungarian referee Viktor Kassai, feeling that the sending off of Arturo Vidal was unjust and that two of Cristiano Ronaldo's three goals were offside.
"When he has to be, he is. To score six goals against a team like Bayern Munich isn't easy, so we deserved to go through", added Ronaldo.
Real boss Zidane said: "We played 120 minutes and in the end, some players have finished a bit worse for wear". "The calls made by the referee hurt us a lot. "(Bayern president) Uli Hoeness and I, we've taken many blows.
And after the game, with the traveling Bayern fans kept in the stadium, Kroos took his son onto the pitch so he could score a goal.
The Spanish side had won the initial leg 2-1, allowing them to bring the advantage of two away goals into their home leg.
Few players could do what Ronaldo is doing.
"We had thought of everything going into this game - except the referee", Ancelotti was quoted as saying by the BBC on Wednesday.
Bayern Munich dropped a disappointing 4-2 decision to Real Madrid on Tuesday - but the loss of starting goalkeeper Manuel Neuer for the remainder of the season may hurt more than the game did.
"I think everyone was a witness to a game that wrote history today", Rummenigge said.
Ancelotti will also reflect that his best eleven is very close to the required standard, even if the depth in his squad to cope with two or three important absences is not there.
"The big teams are Bayern, Barcelona, Real Madrid, especially in the financial aspect", he said.
Bayern Munich players and Carlo Ancelotti criticize a lot the referee: "Referee's job is hard, I never talk about them. The first day I got here, my only goal was to turn Atletico into a competitive team that could contend in all competitions that it played".