Now White slipped up with . . . .

. . . and lost quickly after . . .

Reaching for the hole on d6 to become an octopus.

The immediate 20.Nd6 was also good.

With his last move Black had prepared 21 . . .Bf5 , so Grischuk decides to land the octopus. Within three moves White has established a big space advantage, which is practically winning.

. . . and White converted his advantage.

The most direct approach to gain further entrance on the queenside and eliminate Black's attacking bishop. True, White is very comfortable, having made considerable headway on the queenside already.

The attempt to preserve the bishop with 22...Bd7 runs into 23.b5 Rxa1 24.Rxa1 Rh6 25.Nc6 Qe8 26.Ra8 when Black's
attack is not strong enough.