By Daniel Alvarenga
LISBON, Nov 9(Reuters) - Benfica's Oscar Cardozo scored a hat-trick in a 4-3 extra-time win over Lisbon rivals Sporting in the Portuguese Cup last 32 on Saturday with Luisao grabbing the winner after a blunder by visiting keeper Rui Patricio.
Luisao scored in the 97th minute when, despite falling in the area trying to pounce on a cross, he managed to send a weak header goalwards that Sporting's Portugal keeper somehow allowed to slip between his legs to the dismay of his team mates.
The two fierce rivals, who are level on points in second place in the Portuguese Premier League behind Porto, treated fans to a thrilling Cup tie at the uz Stadium.
Benfica, the Cup runners-up last year to Vitoria Guimaraes, had doubts over the fitness of striker Cardozo, who picked up an injury in Tuesday's Champions League loss to Olympiakos Piraeus, but he started and wreaked havoc on the Sporting defence.
The Paraguayan opened the scoring with a clever free kick after 12 minutes, firing under the wall as the players jumped.
The visitors equalised through Spanish winger Diego Capel's first-time volley in the 37th but Cardozo was unstoppable.
The lanky 30-year-old, Benfica's top foreign scorer of all time, hovered in the air to head them back in front and blasted the ball into the top corner to make it 3-1 before the break.
Sporting's Brazilian centre back Mauricio began a second-half comeback by towering above the home defence to score from a corner just past the hour mark.
There were plenty of chances for both sides on an evening of delightful attacking football.
Lazar Markovic hit the bar for Benfica and Patricio saved at Cardozo's feet before Sporting's Algerian striker Islam Slimani came off the bench to make it 3-3 with a stoppage time header that took the match to extra time.
Patricio then gifted Benfica the winner before Slimani headed just wide for the visitors and the home side's Andre Gomes hit the post, while Sporting's Marco Rojo was dismissed for a second booking five minutes from the end. (Editing by Ken Ferris)