Manchester - Frank Lampard demonstrated his worth to Premier League champions Manchester City with the winning goal in an extraordinary 3-2 home victory over Sunderland on New Year's Day.
His 73rd-minute goal, a six-yard header from Gael Clichy's cross, completed a breathless sequence of five goals in 16 minutes in which the hosts went 2-0 up, squandered their lead, and moved in front again.
Just four days after they had allowed Burnley to come from two goals down and force a 2-2 draw at the Etihad Stadium, City appeared on course to suffer the same fate against Sunderland.
But Lampard's goal, which arrived a matter of hours after City extended the 36-year-old's loan move until the end of the season, enabled Manuel Pellegrini's side to keep the pressure on leaders Chelsea.
Lampard's loan move, from City's sister club New York City, has been highly controversial, with fans of the new American franchise complaining bitterly about the behaviour of the Premier League side.
But if City manager Pellegrini was looking for vindication of his club's conduct, it was not long in coming, with Lampard finding the target just three minutes after entering the fray as a replacement for Stevan Jovetic.
Yaya Toure, making his last appearance before the Africa Cup of Nations, had sparked the remarkable goal flurry in the 57th minute, when City finally broke down Gus Poyet's dogged and defence-minded visitors.
Clichy found Jovetic in the area with a cross and the forward's short pass fell to Toure, who used the outside of his foot to score with a magnificent 22-yard strike.
Jovetic claimed the second himself just nine minutes later with a goal every bit as enjoyable as Toure's.
Again, full-back Clichy created the opening, with a low cross into the six-yard area that allowed Jovetic to lose his marker and convert with a skilful back-heel.
That should have been sufficient for City to coast to victory, especially with their chastening experience against Burnley on Sunday fresh in their memories.
But two minutes later former City midfielder Jack Rodwell rose unmarked just six yards from goal and steered Sebastian Larsson's corner into the back of the net with a glancing header.
And just three minutes after that, Sunderland drew level, after Pablo Zabaleta sent Billy Jones flying inside the hosts' penalty area following a fantastic run and cross by substitute Ricardo Alvarez.
Another former City player, winger Adam Johnson, strode up and placed an unstoppable left-foot penalty kick past Willy Caballero, a stand-in on the day for rested England goalkeeper Joe Hart.
There had been no indication of such a goal frenzy in the first half, with the visitors implementing Poyet's game-plan perfectly and packing 10 men into their own penalty area in an attempt to frustrate their hosts.
While David Silva extended visiting goalkeeper Costel Pantilimon with a shot from outside the box, Caballero was also required to repel a free-kick by Larsson.
But after the goals had come, and the game finally opened up, City could have won by a far greater margin.
Pantilimon, a former City player, saved from Lampard and Jesus Navas, while Toure almost walked the ball into the net and Fernandinho and James Milner were each guilty of glaring late misses.