Julen Lopetegui expressed frustration after his Porto side suffered what he felt was an undeserved 2-0 loss at home to Benfica on Sunday.
A brace from Brazilian striker Lima gave visitors and league leaders Benfica maximum points in O Classico at Estadio do Dragao, a victory that puts the Lisbon club six points clear of Porto at the top of the Primeira Liga with a game to go before the mid-season break.
However, Lopetegui was left annoyed at Porto's failure to take anything from a match that he believed they dominated as they slipped to a first league defeat of the season.
"Football was unfair," Lopetegui said. "We were absolutely superior, we were on top of them all game, but it is not worth points, goals are worth points.
"I am disappointed with the result but not the display. I believe we were very, very, very superior to Benfica.
"We wanted to be level at the top. We will continue to work. There are still a lot of points [to win]."
Meanwhile Benfica boss Jorge Jesus praised the defensive performance of his team.
"Benfica was an effective team with experience and defensive quality," Jesus said. "We neutralised almost every Porto [attacking] situation. We were deserved winners.
"Tactical balances are what define teams. We neutralised the corridors of Porto and waited for our opportunities. We were a realistic and effective team."