George Boyd's sumptuous half-volley earned Burnley a precious win in their survival battle and dealt Manchester City another Premier League title setback.
The Scotsman's 61st-minute strike was enough for the Clarets to secure a 1-0 win at Turf Moor which takes them within one point of 17th-placed Sunderland.
City, meanwhile, remain five points behind Chelsea at the top of the table, having played two games more, and their season now arguably hangs on their return leg against Barcelona in the Champions League on Wednesday.
Neither goalkeeper had a save to make in the opening half an hour and Tom Heaton was only minimally worked thereafter as the Clarets, who were previously winless in seven league games, more than held their own.
Sam Vokes was starting a Premier League game for the first time following a long-term knee ligament injury and headed well wide after rising high to meet a Kieran Trippier cross.
City's clearest opening came when Fernandinho squeezed a pass through for Edin Dzeko and his shot from a tight angle was blocked by Heaton, who also saved Sergio Aguero's tame follow-up effort.
Scott Arfield called Joe Hart into action with a low shot from 25 yards shortly before Aguero sliced wide from a good position as a lively five-minute period threatened to spark the otherwise passive champions into life.
The Citizens were just as off colour at the start of the second period as a rare poor touch from David Silva took him irrecoverably wide of the Burnley goal after Aguero had cleverly spun Arfield on the halfway line.
It was then the Argentine's turn to squander a good chance as he guided wide at the near post from Pablo Zabaleta's cross, while Boyd had Hart scrambling at the other end with a right-footed volley which drifted wide.
The former Hull City winger had the beating of the England international stopper minutes later as he met Vincent Kompany's clearing header on the bounce with the sweetest strike of his left foot into the bottom corner.
Burnley defended their lead stoutly as Jason Shackell blocked Yaya Toure's powerful shot and Heaton denied Wilfried Bony, who replaced Dzeko in one of three second-half changes which also saw Silva and Toure hooked.
Aguero headed over when unmarked at the far post and Zabaleta was denied a penalty by referee Andre Marriner in stoppage time to ensure that City head to the Camp Nou on the back of again failing to cut the gap on Chelsea.