Athletic Club started the 2018/19 season off with a victory over Leganes, but they have not won again since then and have now gone seven matches without a win.
Most recently, they visited Basque neighbours Eibar at Ipurua and could only manage a 1-1 draw.
The team from Bilbao should probably feel glad to be taking anything back up the AP-8 motorway, with Los Armeros having been the better side and having been the ones in the lead.
VAR was consulted to help Eibar open the scoring in the 17th minute, with Inigo Martinez judged to have fouled Sergi Enrich, and with Charles stepping up and converting the spot kick.
Athletic were able to level almost immediately, as Inaki Williams finished well when breaking through on goal in the 21st minute.
Following that, though, Eibar retook the initiative and ended the game with 18 shots and six of them on target, compared to the six and three of their guests.
The best chance for the home side came in the 62nd minute, when Athletic goalkeeper Iago Herrerin had to make two saves in quick succession from Fabian Orellana and then Joan Jordan.
The visiting goalkeeper, who replaced Unai Simon for this one, was equal to everything except Charles' penalty and earned his side a point.