Costinha's late equaliser at Old Trafford fired FC Porto into the quarter-finals of the UEFA Champions League as Manchester United FC crashed out 3-2 on aggregate.
Costinha pounced on to a rebound to score after Tim Howard could only palm away Benni McCarthy's free-kick in the final minute. The strike cancelled out Paul Scholes's first-half header which had put United in command on the away-goals rule.
Saha sits out
United made three changes from the side which lost the first leg 2-1, two enforced with their goalscorer in Porto, Quinton Fortune, injured and captain Roy Keane suspended. John O'Shea came in at left-back, while Eric Djemba-Djemba started in the centre of midfield. Scholes was paired up front with Ruud van Nistelrooij instead of Louis Saha with Darren Fletcher on the right side of midfield.
The Portuguese league leaders, again without long-term injury victims Derlei, César Peixoto and Marco Ferreira, made one change, Costinha returning to the side after suspension in place of the injured Pedro Mendes.
Porto, 4-0 losers on their last visit to Old Trafford in the 1996/97 quarter-finals, were pressed back into their own half from the outset and were soon under pressure. Van Nistelrooij was pulled down by Paulo Ferreira on the left side of the area on ten minutes, but from the free-kick Scholes shot wide.
Having held firm at the back, Porto began to take the game to United, who exploited the extra room to start carving out chances. Twice Ryan Giggs cut through on the left, but the first clear sight of goal came on 23 minutes, when Costinha's misplaced pass fell to Van Nistelrooij whose forward run into the box was stopped by Vítor Baía's brave dive.
Neither side was able to take command, and when the first goal came it resulted from the best passing move of a scrappy first half. On 32 minutes Giggs sent O'Shea down the left and the Irish international cut the ball back beautifully before crossing to the near post where Scholes glanced in his first Champions League goal of the season.
Now in front on away goals, United looked to press home their advantage. On 35 minutes a Giggs shot was well saved by Vítor Baía, and the luck appeared to be going United's way when Jorge Costa hobbled off injured to be replaced by Pedro Emanuel.
Howard to the rescue
Three minutes later, however, a mistake by Djemba-Djemba almost let Porto back into the game, Howard saving excellently with his legs from close range after Carlos Alberto had been gifted the ball by the Cameroonian's scuffed clearance. Porto were enjoying their best spell of the match, but when it looked like United would be grateful just to reach half-time in front, Scholes touched in at the other end, only for the goal to be disallowed for offside.
Djemba-Djemba was taken off at half-time with damaged ribs, allowing Saha to arrive, but it was Porto who were back on the attack, Brown brilliantly blocking Maniche's powerful strike soon after the restart. Three minutes later Carlos Alberto sent a shot wide from the edge of the area as Porto continued to put the United back four under pressure.
Dmitri Alenichev shot over when well-placed on 68 minutes, but United were beginning to threaten on the break as Porto chased the game. The closing stages were largely played out in the United half, but just as it looked like the English champions had held their nerve, Costinha struck.