Real Madrid were held by Atlético Madrid on Saturday, but the Bernabéu boss opined that his side were vastly superior to the visitors.
Madrid went into the derby having suffered a comprehensive 3-0 defeat at Sevilla on Wednesday, and at times in the first half they looked destined for another loss.
Their goalkeeper Thibaut Courtois had to be at his best to keep the score level at the break, denying Antoine Griezmann and Diego Costa in one-on-one situations.
Madrid were better after the break and controlled much of the second half, though clear-cut chances remained infrequent.
Nevertheless, Lopetegui is convinced his team were vastly superior to their visitors.
"We were the better team by far, but if you don't score a goal, then, obviously, you can't win," he told reporters.
"The goals will come, I don't have any doubts about that. We created a lot of chances, and if we keep doing that then I've no doubt the goals will flow.
"Atlético are a great team. They have joined the elite with some magnificent signings, they've a spectacular squad.
"They are contenders to win everything, so I'm happy because we were better than a great team."
Lopetegui and Madrid suffered the blow of losing Gareth Bale to a thigh injury at half-time, but his replacement Dani Ceballos injected some much-needed craft and the coach applauded his impact.
"Gareth felt something in his adductor in the first half," Lopetegui added. "He came off as a precaution and will have tests tomorrow, so we will see what he actually has.
"Dani came on today and did fantastic. He played very well when the team was more balanced and playing better in the second half.
"That meant we won the ball back a lot in their half. Dani showed the personality and character he has, his physical and technical gifts."