Board 3 of Morphy's five-board simultaneous at the St. James's Chess Club, 26 April 1859. A Petroff's Defence and the only game Morphy lost in the display, Mr. Barnes conducting the defence with great precision.
12…Bc5+Playing Q. to K. B's 2nd, or to K's sq., would only lose the exchange, as White would rejoin with Q. to Q's sq. (ch.), and then capture R.
17.Bd2Intending, probably, to advance P. to Q. B's 4th; but it would have been much stronger play to post this B. at K's 3rd.
19…Nb6A very subtle, clever move, the true motive of which White entirely overlooked.
20.Qxb7Curiously enough, this move, as Black foresaw, costs White his Kt.
24…Qf7Had Black taken B. with Kt., White would have captured B. with R. (ch.), at least regaining the piece, with an attacking situation.
26…Qh5Menacing mate, and capitally played.
27.Rf4On examination, it will be found that any other move loses the game quickly.
28…e2The timely march of this Pawn decides the game, and is effected in excellent style. White has no choice but to take the Queen.
32…Qf1+An uncommonly beautiful move; if White takes Queen, Black gives mate at once.
J. Löwenthal, Morphy's Games of Chess (1860) · Public domain · source