* Barca thrash PSG 6-1 to reach Champions League quarter-finals
* Roberto late strike sends Barca through 6-5 on aggregate
* Cavani volley looked to have killed tie off in second half Neymar scored twice in three minutes before Roberto struck
* Barca through to last eight for 11th year in a row
BARCELONA, March 8 (Reuters) - Barcelona became the first team in Champions League history to overturn a four-goal deficit in a knockout tie as a stoppage-time goal by Sergio Roberto completed an extraordinary 6-1 victory over Paris St Germain on Wednesday.
Edinson Cavani looked to have wrecked Barcelona's dreams by volleying in an away goal to make the score 3-1 but two late strikes from Neymar set up a thrilling finale before Roberto scored to seal a 6-5 aggregate win for the Spanish side.
Barcelona began to believe in the impossible dream of clawing back their shock 4-0 loss from the first leg when Luis Suarez headed over the line in the third minute and a Layvin Kurzawa own goal gave them further hope before the break.
Lionel Messi's penalty five minutes into the second period had the Nou Camp on its feet but Cavani's strike in the 62nd was a sucker punch to Barca's ambitions from which Luis Enrique's side took a while to recover.
A curled free kick from Neymar in the 88th minute gave them hope and the Brazilian converted a penalty in the 91st before substitute Roberto slid in to knock the ball beyond Kevin Trapp from a chipped free kick and send Barca through to the last eight 6-5 on aggregate. (Reporting by Richard Martin)