Athletic's San Mames is one of the toughest away trips in Spain and Real faced another gruelling match even without any fans in the stadium, as the Basques continually closed them down and subjected them to their usual aerial bombardment.
Athletic goalkeeper Unai Simon attempted to distract Ramos but the veteran defender maintained his composure to seal the important victory while scoring a 22nd consecutive penalty for club and country and move into double figures for goals this season.
That result not only strengthened Madrid's position at the top of the table but continued their perfect start since returning from lockdown.
Zinedine Zidane's side have won six games from six and have now not conceded in their last three.
Barcelona can cut Madrid's advantage back to four points when they travel to Villarreal later on Sunday, but having won only once in their last four games the upper hand in the title race is with Madrid.
Information from Reuters was used in this report.