AC Milan are hoping to become only the second team to recover from losing the home leg of a UEFA Champions League tie as they travel to FC Barcelona.
Although home defeats in the first leg of the UEFA Champions League knockout rounds are not especially rare, an overall victory by the losing team is an unusual commodity. For AC Milan to overcome the odds - and FC Barcelona - and reach the final for the second successive season, they have to do what no side has managed since AFC Ajax ten years ago.
Odds against Milan
• In 14 seasons of the UEFA Champions League, Ajax's achievement in recovering from a 1-0 reverse at home to Panathinaikos FC in the 1995/96 semi-finals to win 3-0 in Athens stands alone.
• Such is the task facing last year's runners-up after Ludovic Giuly's second-half strike sparked Barcelona celebrations at San Siro last week. Now, in their 100th UEFA Champions League match, the Spanish team will be hoping to book a place in the 17 May final in Paris. It would be only their second in the competition since its revamp for the 1992/93 campaign.
• Barcelona's triumph in Milan maintained their impressive away record in this season's tournament, Frank Rijkaard's men recording four wins and two draws in six fixtures so far. They have conceded just once in those outings and that was an own goal by Thiago Motta in the last-16 first leg at Chelsea FC.
• Barça's confidence will be further boosted by their unbeaten run at the Camp Nou. Following their home loss to Juventus in the quarter-final second leg in 2002/03, they are undefeated in nine matches at their home ground, winning seven and drawing two.
• In this campaign they have won four and drawn one at home, with a goal difference of 15-3.
• Against visitors from Italy, Barça have suffered two reverses with eight victories and three draws. Milan were one of the two visiting teams to lower the Catalan club's colours, winning 2-0 in the 2000/01 first group stage.
Last year's revenge
• The sides met again in last term's group stage with Barcelona gaining a measure of revenge with a 2-1 scoreline at home. Samuel Eto'o levelled matters after Andriy Shevchenko had put the visitors ahead. Ronaldinho then registered the winner with a minute remaining.
• In all Milan and Barça have played each other ten times and, remarkably, have identical records: P10, W4, D2, L4, F14, A14.
• Their most memorable encounter came in the 1993/94 showpiece, which produced the largest winning margin of the 13 UEFA Champions League finals to date. Milan triumphed 4-0 in Athens with a masterly display of attacking football that blew Johan Cruyff's fancied team away.
• Milan lost to Real Madrid CF in the 1957/58 European Champion Clubs' Cup final in Brussels, going down 3-2 after extra time.
Super Cup contest
• The sides, both competing in their tenth UEFA Champions League campaign, also faced off in the 1989 UEFA Super Cup with a 1-1 draw in Spain preceding Milan's 1-0 success at San Siro.
• In their fourth UEFA Champions League semi-final, Barcelona are hoping for a better outcome than in their previous two which both resulted in defeat - against Real Madrid in 2001/02 and by another Spanish rival, Valencia CF, two years earlier. Their first venture into the last four of the UEFA Champions League, in 1993/94, produced a 3-0 home win against FC Porto in a one-off fixture.
• Their only triumph in the European Cup came when they ousted Italian opponents UC Sampdoria 1-0 in the 1991/92 final at Wembley. Coincidentally, the same team suffered when Barça lifted the 1988/89 UEFA Cup Winners' Cup in Berne with a 2-0 victory.
Four in four
• The Rossoneri will be desperate to safeguard their record of never having lost a UEFA Champions League semi-final: four appearances, four successes. But the defeat that ended a sequence of 13 unbeaten European games at San Siro – comprising 12 wins and a draw – threatens their hopes of making it five in a row.
• Milan's 2-0 victory at the Camp Nou in 2000/01 was the first of three wins in Spain, with successes at RC Deportivo La Coruña following in each of the next two campaigns. Milan have, however, lost on three of their last four visits with the other match – at RC Celta de Vigo in the 2003/04 group stage - finishing in a draw. In 17 trips to Spain, Milan have won three times and drawn four.
• Their progress to this stage has been achieved largely thanks to their home form, seeing off first FC Bayern München and then Olympique Lyonnais in the knockout rounds. The Italian club recorded second-leg victories by 4-1 and 3-1 respectively at San Siro following away draws.
Just one win
• Milan have won just once on their travels in this season's competition when, on Matchday 5, Shevchenko scored a UEFA Champions League record-equalling four goals in a 4-0 thrashing of Fenerbahçe SK in Istanbul, the city in which Milan had suffered heartbreaking defeat in last year's final. Carlo Ancelotti's players had raced into a 3-0 lead against Liverpool FC only to lose on penalties.
• The away leg of the 2004/05 semi-final was not a comfortable experience for Milan. They had won the home game against PSV Eindhoven 2-0 through Shevchenko and Jon Dahl Tomasson but then succumbed 3-1 in the Netherlands with only an added-time effort from Massimo Ambrosini taking them through on away goals.
• Shevchenko remains the leading scorer in this season's tournament with nine goals and coach Ancelotti will be hoping Filippo Inzaghi recovers from the virus that ruled him out of the first match to play alongside the Ukranian. Inzaghi struck against Bayern and Lyon, and has four goals in the tournament.
• Barcelona, who boast the competition's second top scorer in seven-goal Ronaldinho, will be able to call on Deco after he was suspended last week. Their progress to this stage was more assured than Milan's, as they followed a 0-0 draw at SL Benfica in the quarter-final first leg with a 2-0 home success. The goals came in either half from Ronaldinho and Eto'o, and they could even afford a first-half penalty miss from the Brazilian.