A Soviet built Polikarpov Po-2 is the only biplane ever credited with downing a jet fighter in combat, says Wikipedia.
Po-2 biplanes were used by NK to run "bed check Charlie" night air raids on US troops in the Korean War.
Made of wood and cloth, its radar signature was quite stealthy. And boy was it slow.
Seems an American throttle-jockey over Korea allowed his Lockheed-built F-94 to stall out and crash when he tried to slow down enough to blast the slow NK foe.
The source article about the F-94 incident appears to be only accessible with an Air Force Association membership, something I don't have.
Grier, Peter. "April 15, 1953". Air Force Magazine, Air Force Association, June 2011, p. 57.
What a Po-2 looks like in flight, via YouTube...
The Po-2 is also noted for its role in World War II where female Russian pilots flew them in night raids to harass opposing German forces, thus the term "Night Witches" noted on the video.