Read a full match report of the Premier League match between Manchester City and Sunderland at the Etihad Stadium on Wednesday 16 April, 2014

Liverpool always hoped Connor Wickham would score the goals to nudge them towards the title. This utterly absorbing league campaign was given a further twist when Wickham, the Sunderland forward who so nearly moved to Liverpool during Kenny Dalglish’s second spell as manager there in 2011, delivered two goals which could help the league trophy end up at Anfield for the first time since Dalglish’s original reign.

Wickham’s brace carried significance at both ends of the Premier League table, badly damaging Manchester City ’s hopes of catching Liverpool or Chelsea and also giving his Sunderland side a lifeline, albeit slender, of survival. Sunderland are six points from safety with a game in hand. If they play as positively as they did for long spells here, and Wickham turns a prolific cameo into long-lasting substance, then Sunderland have a chance. They would have left the Etihad with even more points and hope had Vito Mannone not spilled Samir Nasri’s late shot.

The presence of the Liverpool midfielder, Jordan Henderson, enjoying the resilience of his old Sunderland team and the ramifications for his current one, simply added to the feeling of symmetry. Sunderland were able to find the £8 million to buy Wickham from Ipswich four years ago, beating more famous suitors like Liverpool, because they were flush with the funds Dalglish had given them for Henderson.

The switch from Suffolk has hardly been a success. He had scored only one league goal for Sunderland in 37 appearances until last night. Wickham has been a wanderer this season, spending time on loan at Sheffield Wednesday and Leeds. Sunderland’s other options had failed, notably Jozy Altidore while Fabio Borini tends to be used wide (although he caught City out in the Capital One Cup final when through the middle). Wickham had tumbled down the pecking order, his heavyweight physique not being imposed on opponents enough. Yet he’s only 21, and one of the few Englishmen to have won an international trophy, the Under-17 European Championships in 2010.

For a tall, muscular forward perceived as occasionally lacking true mobility, Wickham was too quick of thought for City for his first and too fast physically for them in scoring his second for Gus Poyet’s side. Further symmetry was provided by Poyet, who has done his old club Chelsea a huge favour.

Chelsea’s visit to Anfield on April 27 almost assumes the billing of a title play-off now. If Jose Mourinho was never going to allow himself to be written out of the title soap opera early, and he will doubtless arrive at Anfield hoping to exorcise Luis Garcia’s ghost goal from 2005, then City’s drop from the nation’s leading light is unexpected.

Injuries to the likes of Sergio Agüero have slowed them, and the Argentine was limited to just under an hour here. Yaya Touré was absent, attending a strained adductor. Vincent Kompany still does not look fully comfortable, particularly against pace, following his knock in training. David Silva, so often the creative fulcrum, was nursing a slight ankle injury.

Manuel Pellegrini suddenly resembles a house guest trying to come to terms with the relentless intensity and demanding rhythms of life in the Premier League mansion, when upstairs can be invaded by downstairs.

Sunderland, stirred up by Lee Cattermole and the excellent Jack Colback, staged an insurrection in midfield that Fernandinho and Javi García could not quell.

Sunday’s defeat at Anfield had left City no margin for error so this was a calamitous evening. Yet they had started vibrantly, seizing the lead after 114 seconds. Álvaro Negredo hustled Cattermole into ceding the ball and City clicked clinically into gear. Agüero gained good ground through the centre before cutting the ball back from left to right.

Negredo’s dummy wrongfooted Sunderland’s defence and freed Fernandinho. The Brazilian made short work of shifting the ball right-footed between Mannone and the Italian’s left-hand upright.

For all their frustration at events at Anfield, Pellegrini’s side started as if they were not going to ease up in the race for the title. “We’re Manchester City, City, we’ll fight to the end”, chanted their fans, also teasing their guests about the Capital One Cup final. “Did you cry when Yaya scored?” Sunderland had no time for tears; they were too busy causing distress in City’s defence. John O’Shea headed wide and then over. Borini shot wide, so did Johnson. Their profligacy contrasted with Wickham’s later verve and accuracy.

City were chasing a second, appealing loudly for a penalty when Agüero was knocked off balance by the slightest of contacts from Wickham before the break. Stevan Jovetic spent half-time warming up hard, eventually replacing Agüero 10 minutes after the restart. Agüero did not look particularly enamoured by the decision as he took Jovetic’s place on the bench. The Montenegrin was immediately involved, linking with Nasri before the move petered out. Nasri then passed in to Jovetic, who nutmegged Cattermole but his shot was gathered by Mannone. Jovetic was trying to make things happen, to force a second, and attempted an overhead kick which spiralled high and wide.

Sensing City’s Anfield hangover, Sunderland made increasing excursions, Borini’s break stopped by Pablo Zabaleta. Pellegrini replaced Negredo with Edin Dzeko yet it was Sunderland who scored. They were looking far more confident, attacking with increasing threat. Wickham and Johnson combined to set up Colback, whose shot was saved by Joe Hart when a cutback might have proved more profitable.

Sunderland equalised after 73 minutes, their route to goal eased by poor marking and concentration, even a touch of complacency by City. Emanuele Giaccherini’s cross from the left was allowed to continue across goal, all the way through to the unmarked Wickham, who calmly turned the ball home.

Lightning struck twice. Wickham is hardly the most prolific of finishers. Suddenly he doubled his tally in 10 minutes. Released by Giaccherini, Wickham raced through and thumped the ball between Hart and the keeper’s post. It was an emphatic finish but City’s defenders and their keeper will not enjoy seeing the DVD of this.

Sunderland fans were jubilant but a horror show was about to unfold down the other end of the pitch. Mannone only half-stopped Nasri’s daisy-cutter before scrambling vainfully as it dribbled apologetically across the line. City believed again. Their fans willed them on and Nasri squandered a great chance, shooting over but Sunderland, buoyed by Wickham, deserved their point.