Porto knock Sporting out of Portuguese Cup
Extra time ended with the scores locked at 1-1 before Porto goalkeeper Helton snapped the deadlock when he saved Sporting's defender Abel's penalty attempt.
Three players were sent off, while the referee dished out 14 yellow cards in total during the match.
Brazilian striker Liedson opened the scoring for Sporting after he headed home a poor clearance by Porto defender Fernando after 29 minutes.
Porto levelled when Brazilian striker Hulk raced between two defenders to beat keeper Rui Patricio with a powerful shot after 59 minutes.