Simon Grayson was left frustrated by the second goal that allowed Brentford back into a pulsating contest at Griffin Park, but had high praise for goalscorer Lewis Grabban.
The Black Cats looked set to seal three vital points when Grabban's penalty put them 3-1 up on the verge of half-time, but Florian Jozefzoon's free-kick minutes after the break changed the course of the game.
Didier Ndong looked to have won the ball in the challenge that was eventually penalised, before Jason Steele was beaten at his near post by the Dutchman's curling effort.
Grayson said: "Didier won the ball has he won the tackle from behind? Possibly but I think it is a bit harsh.
"We are disappointed that it has gone in from that position. I don't look for excuses, or feel sorry for ourselves that we didn't get a few decisions.
"There were signs we were looking a decent team, obviously the positives of Grabban coming back and playing as well as he did and Duncan too.
"That is all coupled with disappointment because we haven't won the game."
"I thought he [Grabban] was really good, his hold-up play was good," he added.
"He ran out of steam as Duncan did second half.
"You see the quality that he brings too, Callum McManaman was good when he came on.
"Jonny Williams was out injured. We are getting towards where we want to get to in terms of the attacking side.
"We have to put the ingredients together of keeping clean sheets as well as scoring."
Grayson said he did not try to play for the draw in the closing stages of the game, with the Black Cats coming under sustained pressure from the hosts.
The Black Cats boss brought on Callum McManaman, James Vaughan and Lynden Gooch in the latter stages but the trio were unable to make a significant impact. He reiterated that he believes results will turn as his options improve.
He said: "I do it the other week and you get criticised for shoring up. We wanted to try and win the game and be positive in the approach.
"We still felt we would get chances because it was that open. You take Aiden off and Lewis and Duncan ran out of steam, we wanted to be positive but also make sure we didn't lose it as well.
"The strength in depth is now a lot better and you have Jonny Williams who should be fit for next weekend as well.
"I keep saying we have to put the everything together, of keeping a clean sheet which will allow us to go an win a game."Grayson also said that Josh Maja's injury setback is not thought to be serious. The 18-year-old was due to play against Everton U23's on Friday afternoon but withdrew at the last minute after feeling his knee in the warm-up.
He said: "He was down to play against Everton, he felt his knee was a little bit sore. It was a precaution that he didn't play.
"He was in for treatment to see but I don't think it will be anything serious. It was more a precaution."