DWINS: Kasparov injected tension into what had been a game of quiet maneuvering with his provocative 18... Be6!?, and Karpov took up the challenge with 19.f5, which seized space with a gain of tempo. An attempt to to trap the black queen with 19.a5?! would not have worked after 19...Rac8, because 20.Ra4? allows 20...Qxb2 with impunity.
It would have been wrong to snatch a pawn with 21...Bxa4? because of 22.Bb6.
At this point it looked like Karpov had established a solid superiority in space and mobility, and his immediate threat was to trap the queen with 22.Bb6. However, Kasparov produced a deeply ingenious pawn sacrifice with 21...b5!?, throwing the game into tactical turmoil.
On 25...Qa8!, the fork with 26.Nc7 would have been met by 26...Rxb3 27.Qxb3 Qb8 28.Qxb8 Rxb8 with equality.
Karpov could not play 28.Nc7? because of the trap 28...Nf2+! 29.Rxf2 Rxb3 30.Qd1 (30.Qxb3? Qa1+) 30...Qa7! 31.Nxe8 Qxf2 32.Bxe7 Re3! wins the queen.
The point of Karpov's 31.Na7 was that a routine retreat with 31...Qb7 would give him time for 32.b5! with the terrific threat of 33.Nc6!. However, Kasparov was ready with the excellent exchange sacrifice, 31...Rxa7! 32.Rxa7 Rxb4.
After 34.Qxh5, Kasparov effortlessly made a draw with 34...Nf2+!, the first point being that 35.Rxf2? permits 35...Rc1+ forcing mate. The second point was that after 35.Kg1 Nh3+!, White would lose the exchange were he to play 36.Qxh3? Qb6+.