Nemanja Matic's first-half header was enough for the Blues to win, despite Diego Costa missing an early opportunity, Andre Schurrle spurning a number of fine chances and Oscar being denied by Sporting goalkeeper Rui Patricio.
Chelsea top Group G after Schalke and Maribor's draw in the night's other game and next play the Slovenian side twice, seeking two wins and a place in the knockout stages.
Mourinho said: "This is not knockout where goals are fundamental
This is points
We lost two points at home (drawing 1-1 with Schalke), we recovered that.
"Because of the other draw, we put ourselves not in a comfortable position, but in one where we can control our destiny.
"We play two games against Maribor
If we manage six points, that would be 10 (points) and job done.
"Now we have just to focus on beating Maribor, which I believe is not easy
To draw in Germany means something."
The Blues, who next play Arsenal in the Barclays Premier League on Sunday, squandered a host of opportunities to make life more comfortable for themselves in ending Sporting's 16-match unbeaten home run in Europe.
Mourinho made a point of speaking to Patricio at the end of the contest when the goalkeeper continually thwarted the visitors.
"I'm not going to repeat the words, because they would be censored," Mourinho added.
"It had to do with something with spoiling the evening, spoiling the night.
"Games like this can end up 4-0 or 5-0, but it ended up 1-0 and a well managed goal.
"We had to make sure we closed all avenues for them to come back into the game and claim a draw, and that's what we did."
Chelsea captain John Terry told Sky Sports 5: "We had so many chances, it was one of those nights where it just didn't go but thankfully 'Mati' came up with a good header.
"We lost our first game last year and came back to win so that was in our mind, that we had to win."
It was Terry's 100th Champions League appearance and he said: "I'm very proud, there's not too many players to achieve that."
Source : PA