Manchester City defender Pablo Zabaleta accepts the fallen champions are facing a battle to finish in the top four . Zabaleta admits confidence is low with Sunday 's derby loss at Manchester United having continued a dismal run which has seen City capitulate in the Barclays Premier League title race . Manuel Pellegrini 's men crashed 4-2 at Old Trafford , a sixth defeat in eight games in all competitions and a result which leaves them fourth and clinging onto a Champions League place . Wayne Rooney leaps onto Fellaini 's back after United take the lead through the big Belgian , who has had an excellent renaissance recently . It is a far cry from the situation on New Year 's Day , when the defending champions pulled level with Chelsea at the top with a 3-2 win over Sunderland . Having been eight points behind just over a month earlier , City appeared to be clicking into gear - but all has suddenly gone wrong . They now trail the leaders by 12 points , having played a game more , and their form continues to offer encouragement for the likes of Southampton and Liverpool below them . A dejected Yaya Toure and Fernandinho look on following their defeat to rivals Manchester United . Zabaleta said : 'It is time to analyse what we are doing wrong and try to improve for the next few games . There are still 18 points to play for and we must be honest with ourselves and start to push hard , play better and win games , so we can get in the top four . 'When you lose those games it is always really hard , but that is football sometimes . Football is about momentum . 'It seems you lose confidence when you can not get results and it was a really tough afternoon . ' City were chasing a record fifth successive derby win and the occasion initially seemed to rouse them from their recent troubles as they made a blistering start . Sergio Aguero was the rare highlight in an otherwise dismal Manchester City performance at Old Trafford . Aguero scored twice , but he had very little to cheer about as Manchester City left the Eitihad empty handed . Their movement and energy was superb and they claimed a well-worked opening goal through Sergio Aguero after just eight minutes . But that was as good as it got as United equalised through the excellent Ashley Young and then took complete control . Further goals from the impressive Marouane Fellaini , Juan Mata and Chris Smalling secured a convincing win before Aguero 's 100th City goal came as a late consolation . 'It seems we lost confidence and were nervous , ' said Zabaleta . 'Then it was hard for the team to react and we conceded the second goal . Manchester City 's manager Manuel Pellegrini issues instructions as his side lose to their rivals . All of United 's outfield players congratulate celebrate as they score in the derby at Old Trafford on Sunday . 'In the second half we did n't create many chances and when United scored the third goal the game was over . ' Winger Jesus Navas was at a loss to explain City 's failure to impose themselves after United pulled back level . The Spaniard said : ' I do n't really know ( what happened ) . They scored the equaliser and they were back in the game . We started strong but it was n't our day and we need to focus on the upcoming games . It 's Champions League ( qualification at stake ) so we have to fight until the end to be in the top four . ' Juan Mata once again showed his value to the side and pointed the way with a display full of energy and poise .
Current holders Manchester City have capitulated in this season 's title race . Derby defeat to Manchester United leaves them 12 points adrift of Chelsea . Manuel Pellegrini 's side have dropped to fifth behind United and Arsenal . Southampton sit in fourth place five points behind Manchester City . READ : Pellegrini 's job on the line as Patrick Vieira waits in the wings .