Chelsea captain John Terry has admitted that the team played below par during Saturday's win over Crystal Palace in the Premier League.
Fernando Torres's opener was cancelled out by Marouane Chamakh at Stamford Bridge before Ramires netted the decisive goal for the Blues.
Despite moving to within two points of leaders Arsenal following their defeat at Manchester City, Terry concedes that his side found it difficult against Palace.
"Once again we weren't at our best but thankfully picked up the three points and closed the gap on Arsenal, and that is encouragement for us," he told the club's official website.
"Crystal Palace came here on the back of a couple of good wins and they showed a lot of fight and determination and kept going, and while it was 2-1 they were always in the game and they made it difficult at times for us.
"We need to improve, that is clear, and we are doing that and we are still picking up results, so that is very encouraging for us as well. We know we have a higher gear to go to and once we find that, it will be nice to go on a run of wins."
Chelsea are back in action on Tuesday when they travel to Sunderland in the quarter-finals of the League Cup.