I just happened to look at an old booklet about Spassky v PetrosianI by Kotov for Soviet Weekly on the bus to work this morning.

In game 1. Of their 1969 match they reached an ending  with same material as Anand v Gelfand playoff game 2, the decisive game and Spassky could not hold it either despite having more time and the benefit of an adjournment and Petrosian won with a temporary sac of his knight.
Would be interesting to compare Spassky Petrosian vs 7 man table bases  against Anand Gelfand's performance.