Arsenal midfielder Aaron Ramsey says his team's loss to Chelsea affected their performance in the 3-1 win over Olympiacos.
Arsene Wenger's men were never at their best during the Champions League victory at Emirates Stadium, maintaining their perfect start in Group B.
Kostas Mitroglou cancelled out Gervinho's opener before Lukas Podolski restored their lead and Ramsey netted the sealer.
Ramsey, whose side suffered a 2-1 loss to Chelsea in the English Premier League on Saturday, said he was content to get the three points despite their lacklustre showing.
"The performance was always to be expected. After the game at the weekend we were very disappointed and as a result we were a bit sloppy today," he said.
"But as the game went on we gradually got more involved and created a few opportunities and it was a job well done in the end."
Ramsey netted the sealer in the fourth minute of additional time, cheekily chipping his effort over Balazs Megyeri after an Olivier Giroud flick-on.
The Welshman said he hoped the goal would be the first of many this season.
"I didn't score all season at home last year so it was nice to score at home and hopefully now that will get me off the mark again and help me to get a few more goals this season," Ramsey said.
Fellow midfielder Mikel Arteta was also left pleased with the win and said Arsenal's superior fitness was the difference after the break.
"We are really happy because we got the points, we are top of the group now and it was never going to be easy," the Spaniard said.
"The first half they made it really tough for us, but in the second half our superior physical ability was able to make the difference.
"I feel comfortable and if the team wins we are all happy, I am happy."