Real Sociedad went top of Spanish La Liga on Friday (Saturday AEDT) despite only picking up a draw at home to bottom club Leganes.
Mikel Merino put the home side 1-0 up on 63 minutes, but substitute Youssef En-Nesyri levelled from Roque Mesa's cross with 12 minutes remaining.
En-Nesyri's goal gave Leganes' new coach Javier Aguirre his first point since taking over the team midweek.
"The fact that we are top says that we are doing things the right way but this was not the result that we wanted," Real Sociedad midfielder Merino said.
Leganes had defender Kevin Rodrigues sent off on 90 minutes but were happy with the result.
Goalkeeper Ivan Cuellar said Aguirre's 5-4-1 system was a work in progress.
"We have played with that system for a year and a half," Cuellar said.
"The coach wanted that security that it brings us. Now, in the international break, we can work on the tactics that he wants us to use."
Real Sociedad are now a point clear of second-place Barcelona and third placed Real Madrid, having played two more games.