  Consider critical site percolation on $\mathbb{Z}^d$ with $d \geq 2$. We
prove a lower bound of order $n^{- d^2}$ for point-to-point connection
probabilities, where $n$ is the distance between the points. Most of the work
in our proof concerns a `construction' which finally reduces the problem to a
topological one. This is then solved by applying a topological fact, which
follows from Brouwer's fixed point theorem. Our bound improves the lower bound
with exponent $2 d (d-1)$, used by Cerf in 2015 to obtain an upper bound for
the so-called two-arm probabilities. Apart from being of interest in itself,
our result gives a small improvement of the bound on the two-arm exponent found
by Cerf.
