Chelsea manager Jose Mourinho says it was very important for his team to secure all three points against Porto even if they only needed one to reach the Last 16 of the Champions League.
The Blues have been struggling for form in the English Premier League but reached the Last 16 in Europe after suffering only one defeat.
And the Portuguese says the win will give him and his players a lot of confidence ahead of upcoming domestic fixtures this month.
"The thing that I'm most happy with, apart from the result, is the fact we needed a point to qualify and the players accepted the challenge of playing to win," Mourinho told reporters.
"That's not easy when the moment is bad, results are negative and pressure is high. They [the Chelsea players] were brave to accept that challenge. Apart from that I felt the first goal was fundamental.
"When we scored they were in a difficult position because they needed to win, a point wasn't enough for them. We knew we could conceded a goal and still qualify.
"What gives me confidence is the fact that we have been playing okay for the last couple of months, the results haven't been as good as the work we do every day and the way the players are playing. We could have had different results against Stoke, Tottenham, Bournemouth.
"The piece of luck we had with the first goal tonight we've never had in the Premier League. It was a great decision by the official on the goal-line and we never get that in the Premier League, despite the fact it's goal-line technology.
"When the game started both teams were under pressure, when we scored the first goal the picture was different. We were more calm, more relaxed, the players could be in control of the game and the situation for Porto was more difficult."