Danish number one Thomas Bjorn, Ryder Cup star Colin Montgomerie, South African Trevor Immelman and Michael Campbell of New Zealand have confirmed their participation in next month's GBP1.25 million ($18.1 million) Johnnie Walker Classic in Beijing. The quartet's inclusion will make it the strongest field ever assembled for a tournament on the mainland. Asia Pacific's premier event will be played from April 21 to 24 at Pine Valley Golf Resort and Country Club where the event makes its debut on the mainland. These players join a field that includes four of the world's top 10; number three Ernie Els, Retief Goosen at number five, Spain's Sergio Garcia, ranked seven, and number nine Adam Scott of Australia. Also playing will be Korea's number one, Choi Kyung-ju, European young guns Luke Donald and Paul Casey, six-time major winner Nick Faldo and defending champion Miguel Angel Jimenez of Spain. Bjorn is ranked 25th in the world with seven European Tour victories to his credit. He was the first Danish golfer to play in the Ryder Cup. Montgomerie claimed the European Order of Merit for a record seven consecutive years and has won 34 events worldwide since turning pro in 1987. He is ranked 54th in the world. The 25-year-old Immelman became the first player since Gary Player to win back-to-back South African Opens. He is ranked 62nd in the world. Campbell has won 13 times since turning pro in 1993 with one of his most notable victories being the 2000 Johnnie Walker Classic in Taipei, where he beat a powerful field that included Vijay Singh, Els and Tiger Woods.