The Portuguese full-back hadn't featured for the Blues since their 3-1 home defeat against Aston Villa in December, but was pleased with his own display in Lisbon as well as the result.
"We are really happy because we got a good result against a good team, and I am also happy because I was not playing for a long time and I played 80 minutes and helped the team," Ferreira told the club's official website.
"Every day I do my work and try to be in the best condition if the manager wants me, and this game he chose me and I tried to give my best.
"Another day I could do even better but in physical terms I knew that I couldn't make crazy runs so I needed to play with more intelligence.
|A COMPETENT COMEBACK
| PLAYER RATING
|6.5||Usually only seen in a tracksuit on matchdays but responded to his first Champions League start of the season with a solid display before bowing to cramp with 10 minutes left.|
Chelsea are rated at 7.5 with 188Bet to beat Aston Villa 2-0 in the Premier League on Saturday.
Ferreira admitted that it was enjoyable to get back to his home country and hailed Salomon Kalou's decisive winner, which ensured that Roberto Di Matteo's side hold a slender advantage going into their second leg at Stamford Bridge.
He added: "It is always good to be in my country and play in this beautiful stadium as well, but we thought that we could score because we have wonderful players who can decide games."
"It was a wonderful counterattack and Ramires did very well on that side and made space. It was a good ball as well from Fernando [Torres] for Salomon, so it was a good goal and good for him, he deserves it."
The game saw David Luiz and Ramires return to their former club, and 33-year-old Ferreira knows only too well about the threat Benfica pose.
The defender, who spent two years of his career playing for Benfica's rivals Porto, warned that Chelsea need to be cautious if they are to progress to the semi-finals.
"We had to defend also because Benfica are a good side and it was hard work," Ferreira observed.
"Everyone played for the team but it is not over yet. We know Benfica have the capacity to score goals away and we need to be careful as well, but playing at home with our supporters in our stadium we will do everything to pass this stage."