Chelsea didn't do much better than Arsenal on its trip to Italy in the Champions League, leaving English clubs in danger of missing the quarterfinals of the competition for the first time since 1996. Showing the same kind of defensive frailties that condemned Arsenal to a 4-0 loss at AC Milan last week, Chelsea failed to protect an early lead and lost 3-1 at Napoli in the first leg of their round of 16 matchup. In Tuesday's other match, CSKA Moscow scored a last-gasp equalizer to draw 1-1 at home against Real Madrid. While Chelsea still has a realistic chance of turning things around in the return leg at Stamford Bridge, the loss heaped further pressure on manager Andre Villas-Boas, whose self-proclaimed support from owner Roman Abramovich could quickly evaporate if he fails to deliver in the competition the Russian billionaire is most eager to win. Chelsea's recent troubles grew worse even before the kickoff, when the club confirmed that captain John Terry will need knee surgery and will be sidelined for up to six weeks. The visitors still looked set to produce a result when Juan Mata gave them an early lead, but Ezequiel Lavezzi exploited defensive mishaps to score twice and Edinson Cavani added another goal to put Napoli in control. It was also a disappointing night for former Chelsea manager Jose Mourinho, whose Madrid side failed to take its dominant domestic form into Europe. Cristiano Ronaldo put the nine-time European champion ahead with his 36th goal of the season, but CSKA midfielder Pontus Wernbloom scrambled the ball into the net with the last kick of the match in the third minute of stoppage time to equalize for the Russian club. While Madrid holds a 10-point lead over Barcelona to be on course to win the Spanish league, Chelsea has now failed to win for a fifth straight game in all competitions. City routs Porto Manchester City eased past defending Europa League champion FC Porto Wednesday, beating the Portuguese side 4-0 to wrap up a 6-1 aggregate win. Sergio Aguero opened the scoring after just 19 seconds to stretch City's 2-1 first-leg advantage but the English Premier League leader then had to wait until the 76th minute for its second goal. Edin Dzeko, David Silva and David Pizarro completed the rout with goals in the last 14 minutes. Entered into the second-tier Europa League following its elimination from the elite Champs League, City advances to the round of 16 for a match against Legia Warsaw or Sporting Lisbon. Tevez apologizes Carlos Tevez finally apologized to Manchester City Tuesday following a five-month feud that has cost him close to 10 million pounds ($17 million), and could soon return to action for the club after withdrawing an appeal against his latest fines. The Argentina striker has not played for the Premier League leaders since September when he refused to warm up during a Champions League match and only returned last week from a three-month unauthorized absence at home. “I wish to apologize sincerely and unreservedly to everybody I have let down and to whom my actions over the last few months have caused offense,” Tevez said in a statement. “My wish is to concentrate on playing football for Manchester City Football Club.”