18.Qc1

White attacks the Black Rook, which has no safe squares of retreat. Black's next move looks flashy, but it's forced. It must have been Black's intention on playing 17...Ne4. Korchnoi wrote

When my opponent made the move 3.exd5, it was not difficult to guess that he would be happy with half a point. But I must admit that the Hungarian master surprised me when, after trapping my Rook, he then offered a draw. After all, a quick glance at the position is sufficient to realize that any result is possible, only not a draw!

No grandmaster draws for Viktor Korchnoi!

Next move: 18...Rxf2