The NBA started in 1946 or 1949, depending on how you count it (a merger between the BAA and NBL in 1949 resulted in the National Basketball Association but the league sees itself as the descendant of the BAA and the NBL teams were seen as expansion teams. Just in case you were wondering).
By 1956 Bill Russell had arrived to revolutionize the game and in 1959, Wilt Chamberlain joined him. The rivalry they had defined the league until 1980, when the Larry Bird-Magic Johnson rivalry took control.
Both men claimed, correctly, that Chamberlain was the greatest talent ever to play center. Russell won every playoff series against Chamberlain’s team except one in 1967, but Chamberlain did superhuman things.
For instance, in this Game 5 from the 1964 Finals, Chamberlain first erases a dunk attempt by Satch Sanders. Then he goes down and scores on his end.
Then, knowing that Boston liked to run, he beats nearly everyone down court - at 7-1 and about 270, mind - and takes Russell’s full speed dunk attempt out of the air.
And note that the Warriors retain both blocks, with Nate Thurmond grabbing the first and Chamberlain getting the second. The modern idea of forcing an aerial turnover, only to throw it out of bounds, was not yet in vogue.
And if you think well no big deal, keep in mind that Russell could do stuff like this. Both of them were off the charts athletically but Chamberlain was a step beyond even Russell.