A place in the Istanbul final on May 25 beckons if Chelsea and Milan can exploit home advantage and take a commanding lead from their first leg games at Stamford Bridge and San Siro.
Chelsea coach Jose Mourinho, who moved to west London after guiding Porto to Champions League glory last season, is at the helm of a team who have so far swept all before them -- including Liverpool.
Their first trophy of the season came in February from a League Cup final in Cardiff against the Merseysiders, when Mourinho's men came from behind to win 3-2.
Their second trophy could already be sealed by the time they take the field on Wednesday, should Arsenal fail to beat Tottenham Hotspur in the north London derby on Monday.
Champions League success, having bowed out of last season's semi-finals under Claudio Ranieri, would make it an astonishing centenary year for a club that has been transformed since billionaire Roman Abramovich's takeover in 2003.
NEW FORCE
It would also underline Chelsea as the new force in both English and European football, the mantle once worn by Liverpool as they lifted four European Cups and eight league titles from 1976 to 1986.
Milan, who won their sixth European Cup as recently as 2003, have nothing
Top of Serie A in their campaign for an 18th league title, the Italian champions have the class and experience of Paolo Maldini at the back, the creative brilliance of Brazil's Kaka in midfield and Europe's Footballer of the Year, Andriy Shevchenko, up front.
Shevchenko's partner Hernan Crespo, who is on loan from Chelsea, has rediscovered the scoring touch which made him one of the most feared strikers in Italian football.
The Serie A and European Cup double has only been won twice before, by Fabio Capello's Milan in 1994 and city rivals Inter in 1965.
Though they will start out as clear favourites on Tuesday against a PSV wide who reached the last four via a penalty shoot-out against Olympique Lyon, Milan will need to be wary.
Coach Guus Hiddink, whose men were crowned Dutch champions for the 18th time on Saturday, was in charge of the South Korea side who stunned the international game by dumping Italy out of the 2002 World Cup.
Two members of that team, defender Young-Pyo Lee and midfielder Ji-Sung Park, will walk out at San Siro.
Hiddink has already over-achieved this season by coping with the loss of all three of his main attackers from last season -- with Mateja Kezman and Arjen Robben going to Chelsea, and Dennis Rommedahl moving to Charlton Athletic.
But if Hiddink has yet another surprise in store for Italian opponents, San Siro would be just the place to spring it.