Martin puts up a last-ditch attacking bomb with a minute to go, but Sharpe soars through the sky and takes the catch.
Newcastle hold on and are through the preliminary final against Penrith.
Brenton Speed described it as a “famous victory” for the Knights, who have gone from the wooden spoon to a grand final qualifier.
High drama at Eden Park and the Warriors’ premiership hopes are dashed.
“This is an incredible effort,” Billy Slater said on Nine.