The Real Madrid playmaker had appeared on course to earn all three points for the hosts following his well-taken opener, but the Dragons were left to rue a rather flat performance as Aleksandar Mitrovic headed home late on to steal a point for the visitors.
"We are so disappointed at the moment, we played great in the first half but then we faded," Bale told reporters after the game, according to BBC Sport.
"We dug in. It's one of those things, you go so close at one end and then they go up and score.
"We believe we can still do it, we just need to keep working hard. At home we were confident, we were 1-0 up in the 85th minute, it's two points lost."
Wales currently sit in third spot with six points in Group D after four games played.