Despite dominating the first half at St James' Park, Premier League leaders Chelsea found themselves behind three minutes before the hour as Papiss Cisse tapped home Sammy Ameobi's cross.
Another Chelsea chance went begging and Cisse punished them with his second of the match. Didier Drogba pulled a goal back after Steven Taylor had been sent off, but Mourinho's men were unable to rescue a point and slipped to their first defeat of the season.
"[I have] no complaints," the Chelsea boss told BT Sport. "[We were] unlucky, we had lots of chances to score in the first [but] we didn't [take them].
"In the second [half] we had chances, but they defended [well], and the first time they go there [Chelsea's penalty box] they scored a goal.
"Then they get everyone behind the ball against a team that tried everything until the last second.
"We wanted to play more foot but it wasn't possible, no complaints."
However, Mourinho did question Newcastle's ball boys, suggesting they slowed down the release of the ball to help the hosts.
"The ball disappeared," he said. "They hid the ball, but it's not just about the time, they kept doing the same thing.
"It's not the players inside the pitch, it's the kind of strategy that is unfortunately still part of the game.
"We didn’t deserve this, but it is the result we had, we have to accept it and move on."
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