Andy Murray's post-Australian Open slump shows no sign of ending. The three-time grand slam runner-up lost in his opening match at the Sony Ericsson Open to American qualifier Alex Bogomolov Jr, 1-6, 5-7 in Key Biscayne, Florida, on Friday.

"I was trying to get myself back into the match, trying to find ways," Murray said. "But I just didn't have that spark."

The Scotsman hasn't won a set in three matches since he was routed in the Australian Open final by Novak Djokovic.

Following Murray's departure, Serb Djokovic improved to 19-0 in 2011 by drubbing Kazakhstan's Denis Istomin 6-0, 6-1. Djokovic's record is the best to begin a year since Ivan Lendl started 25-0 in 1986.

Murray, meanwhile, has lost nine consecutive sets, a remarkable drought for a player ranked fifth in the world.

Training well

"The same thing happened around the same time last year," Murray said. "I have been practicing well, training well, and then in the matches can't get anything going."

A year ago Murray lost opening-round matches in back-to-back tournaments, including at Key Biscayne as defending champion. This swoon is worse, with consecutive defeats against players ranked outside the top 100.

Donald Young was ranked 143rd when he upset Murray two weeks ago at Indian Wells. Bogomolov is ranked 118th.

While his victory gave US fans something to brag about, the last American in the women's draw was ousted in the second round when Varvara Lepchenko lost to Petra Kvitova 1-6, 2-6.

Defending champion Kim Clijsters needed only 50 minutes to win her opening match, beating qualifier Anastasiya Yakimova 6-1, 6-1. Reigning French Open champion Francesca Schiavone beat Angelique Kerber 6-4, 6-4. No. 3 seed Vera Zvonareva rallied to defeat former No. 1 Dinara Safina 3-6, 6-3, 6-2.

In other men's play, No. 9 Fernando Verdasco lost to fellow Spaniard Pablo Andujar 6-3, 6-7 (3), 4-6. Canada's No. 31 Milos Raonic, at 20 the youngest player in the men's top 50, lost to India's Somdev Devvarman 6-7 (5), 5-7.