Aston Villa honored captain Stiliyan Petrov, who has been diagnosed with acute leukaemia, with an impressive fightback against Chelsea on Saturday, only for the Londoners to triumph 4-2.

Goals from Daniel Sturridge and Branislav Ivanovic looked set to earn a routine win for the Stamford Bridge club until goals from James Collins and Eric Lichaj in the space of three minutes pulled Aston Villa level once again.

Manchester City's challenge for the Premier League title suffered a setback as they were forced to stage a late fightback just to salvage a 3-3 draw against Sunderland at Eastlands on Saturday.

With leaders Manchester United not in action until Monday's trip to Blackburn, Roberto Mancini's side would have returned to the top of the table on goal difference if they had beaten the Black Cats.

Aston Villa captain Stiliyan Petrov has been diagnosed with acute leukemia, the Premier League club announced Friday.

Petrov's illness was discovered in medical tests carried out on the 32-year-old Bulgarian international after he came down with a fever following last Saturday's defeat at Arsenal, the club said.

Reigning champ Novak Djokovic beat a stubborn 21st-seeded Juan Monaco 6-0, 7-6 (7/5) Friday to book a re-match of the 2009 Miami Masters final with Scotland's Andy Murray.

Murray, who got the better of Djokovic in the 2009 title match, reached the final on a walkover when world No. 2 Rafael Nadal pulled out of their semi-final with a sore left knee.

A 10-man medical commission will meet Monday to determine if Italy forward Antonio Cassano can begin playing again following minor heart surgery.

Cassano's club AC Milan announced that it asked the Italian Sports Medicine Federation to gather a panel of experts to analyze the striker's condition.

Arsenal coach Arsene Wenger got a three-match touchline ban from UEFA on Friday for comments directed at the referee after his team's Champions League elimination this month.

UEFA said its disciplinary panel found Wenger guilty of "improper conduct," and fined him €40,000 ($53,000).

Manchester City will be without star striker Sergio Aguero for the Premier League clash against Sunderland with a "stupid" injury, club manager Roberto Mancini confirmed Friday.

Aguero was missing from the City team that drew at Stoke on Saturday with a foot problem.

World number one Novak Djokovic booked a semi-final showdown with Juan Monaco at the Miami Masters by holding off a determined David Ferrer of Spain 6-2, 7-6 (7/1).

"It's always going to tough against David, he's one of the greatest competitors on the circuit," said Serbia's Djokovic, winner of the last three Grand Slams. "I didn't want to get to the third set because physically he's always there."

Three-time runner-up Maria Sharapova booked her second straight Miami final Thursday, rallying to beat disgruntled Caroline Wozniacki and set up a title clash with Agnieszka Radwanska.

Sharapova clinched a 4-6, 6-2, 6-4 semi-final victory over the Dane after two hours, 34 minutes, the match ending in acrimony as Wozniacki objected to the chair umpire's overrule of a call to Sharapova's benefit on match point.

Brazil coach Mano Menezes says he has doubts over whether Kaka can force his way into the 2014 World Cup team, putting the onus on the Real Madrid player to prove he is worthy of a spot.

Menezes told Brazilian channel SporTV on Thursday that he thinks Kaka could be key for Brazil in the World Cup, but said "next season will tell if Kaka can still play for Brazil in a World Cup. We all have doubts."