Opening Evolution - Phiidor Countergambit (part four)

ENGLAND'S Jonathan Mestel prepared the Philidor Countergambit for the 1975 world U20 championship, held in Tjentište, Yugoslavia.
He surprised Paul van der Sterren with it in round eight, winning in 33 moves.
In the 13th and final round he tried it again, in a game that would decide the destination of the bronze medal.
Peter Nurmi - Mestel
1.e4 e5 2.Nf3 d6 3.d4 f5!? 4.Bc4!?
Although this move is only fourth-most popular, behind 4.dxe5, 4.Nc3 and 4.exf5, it is the choice of Stockfish10 and Komodo10.
4...exd4!?
This seems to have been the first time the move was played, but it was to become Black's first choice ahead of 4...fxe4.
5.Ng5 Nh6 6.Nxh7?!
Hoping to follow up with 6.Qh5+, but Mestel prevents this. Almost certainly better is 6.0-0, which Andras Adorjan used in a win over Mestel at the 1977 European team championship.
6...Ng4 7.Nxf8 Kxf8 8.exf5
8.Qxd4 Nc6 9.Qd5 Qe8 was played with a roughly equal position in Maxim Sorokin (2510) - Evgeni Maljutin (2435), 58th USSR championship (Moscow 1991), although Black won in 23 moves.
8...Qe7+ 9.Kf1 Bxf5

White to make his 10th move

*****
*****
*****
*****
*****
10.Qxd4??
Nurmi presumably missed that this move would cost him the exchange. The engines give 10.Nd2 with a small edge to Black.
10...Nxh2+ 11.Rxh2
Not 11.Kg1?? Qe1+ 12.Bf1 Qxf1#.
11...Rxh2 12.Be3 Qe4 13.Qxe4 Rh1+ 14.Ke2 Bxe4 0-1
I suspect at club level this game would have gone on, but the engines reckon Black's advantage is worth more than a piece, never mind the exchange.