Green’s Dictionary of Slang

(orig. boxing) the fist; thus a type of blow (see cite 1901) and as v. to knock someone down.

1863		G.A. Sala Breakfast in Bed 4: And who, in return for a craven blow, can deliver the auctioneer well over the face and eyes.
1873		in Sl. Dict. 74: Auctioneer to ‘tip him the auctioneer,’ is to knock a man down. Tom Sayer’s right hand was known to pugilistic fame as the auctioneer.
1882		Sydney Sl. Dict. (2 edn) 1: Auctioneer - Tom Sayers’ right was known to pugilistic fame as ‘the auctioneer.’ To ‘tip him the auctioneer,’ is to knock a man down.
1891		F.W. Carew Autobiog. of a Gipsey 84: I steps aside, quick like, and tips him the auctioneer on the jaw.
1895		C. Crowe Aus. Sl. Dict 5: Auctioneer, to knock a man down. John L. Sullivan’s right hand was known to pugilistic fame as the auctioneer.
1901		Sydney Sportsman (Surry Hills, NSW) 3 July 2/4: A downward, choppy, short-arm swing, closely resembling the blow known as the ‘auctioneer’.
1909		J. Ware Passing Eng. of the Victorian Era 11/2: Auctioneer (Peoples’). The fist because it ‘knocks down’ .
1923		J. Manchon Le Slang 55: auctioneer, s. B. to tip the auctioneer to a person = to knock him down.