President Barack Obama lauded Muhammad Ali Saturday as he joined a host of celebrities in offering birthday wishes to the boxer known simply as "The Greatest."

"Happy birthday, champ," Obama told Ali through a video message, saying he wished he could have attended the swanky dinner gala in Las Vegas featuring some of the biggest names in sports, film, television and music.

AC Milan striker Zlatan Ibrahimovic on Saturday urged Arsenal captain Robin van Persie to jump ship if he wants to win anything.

Van Persie's side were thrashed 4-0 by Ibrahimovic's Milan in the San Siro on Wednesday, to effectively end the London club's Champions League hopes.

Victoria Azarenka admits that her bid to win two Middle East tournaments in as many weeks is an emotional one as the young Belarussian returns to Dubai where she nearly quit the game a year ago.

This time last year the 22-year-old from Minsk thought she would quit the women's tour after early defeats in Doha and Dubai.

Former Queens Park Rangers manager Neil Warnock made a swift return to football on Saturday after being confirmed as the new boss of Championship side Leeds.

Warnock, controversially fired by QPR last month after successfully guiding the Londoners into the Premier League, began his reign by vowing to return the Yorkshire giants to the top-flight.

Milan striker Zlatan Ibrahimovic, whose biography has sold more than 500,000 copies, is following up on the success by launching his life story as an interactive iPad app.

Sara Ohrvall, a spokeswoman for Swedish publisher Albert Bonnier, said the "I am Zlatan Ibrahimovic" application, based on the paperback biography with the same name, "is the first interactive biography app in the world."

Dutch coaching legend Guus Hiddink is on the verge of signing an 18-month contract with Russia's Anzhi Makhachkala that will make him one of the world's highest-paid managers, news reports said Friday.

The Sport Express daily said the 65-year-old manager will sign a deal with tycoon Suleyman Kerimov's club after joining them in Belek, Turkey, where Anzhi are currently training.

Manchester United and Manchester City shrugged off the disappointment of being dumped out of the Champions League to inch confidently closer to the Europa League last 16 on Thursday.

United defeated Ajax in Amsterdam 2-0 with Ashley Young and Javier Hernandez finding the target in the first leg of their last-32 tie.

Carlos Boozer scored 23 points, pulled down 15 rebounds and handed out five assists as the Chicago Bulls again overcame the absence of Derrick Rose to outlast Boston 89-80.

Luol Deng and Joakim Noah on Thursday also had "double-doubles" for Chicago, Deng contributing 23 points with 10 assists and Noah scoring 15 points with 16 rebounds.

Behind concrete walls and with no men in sight, Saudi women wearing shorts and short-sleeve shirts meet three times a week to play football in an all-female club in Saudi Arabia's port city of Jeddah.

Cheering them on is Jeddah King's United coach and striker Rima Abdullah, who is also leading a campaign in the ultra-conservative Muslim country to allow women to participate in sports and compete internationally.

The city of Manchester were hoping to see their two football sides fight out the Champions League final, but instead on Thursday both sets of fans will have to make do with the lesser fare of the Europa League.

However, both face tricky second round ties if they are to progress a step closer to the final on May 9 in the mundane surroundings of Bucharest rather than the glamour of the Champions League final in Munich on May 19.