  Currently, the $\Lambda$ Cold Dark Matter model, which relies on the
existence of cold dark matter and a cosmological constant $\Lambda$, best
describes the Universe. However, we lack information in the high-redshift ($z$)
region between Type Ia Supernovae (SNe Ia) (up to $z=2.26$) and the Cosmic
Microwave Background ($z=1100$), an interval crucial to test cosmological
models and their possible evolution. We have defined a sample of 983 Quasars up
to $z=7.54$ with reduced intrinsic dispersion $\delta=0.007$ which determines
the matter density parameter $\Omega_M$ with the same precision of SNe Ia.
Although previous analysis have been used Quasars as cosmological tools (e.g.
Risaliti and Lusso 2019), this is the first time that high-redshift sources, in
this case Quasars, as standalone cosmological probes yield such tight
constraints on $\Omega_M$. Our results show the importance of correcting
cosmological relationships for selection biases and redshift evolution and how
the choice of a golden sample reduces considerably the intrinsic scatter. This
proves the reliability of Quasars as standard cosmological candles.
