  In planar two-loop integrals there is a dedicated sector such that when its
index is zero, the two-loop integral decomposes into the product of two
one-loop integrals. We show an alternative reduction strategy for these sectors
when their index is negative using the Baikov representation. This reduction
strategy is free from the Laporta algorithm. It follows a top-down approach and
is much faster than approaches based on the brute-force, conventional
integration by parts identities.
