Victoria Azarenka has won the Qatar Open for the second year in a row after defeating Serena Williams 7-6 2-6 6-3 in a hard-fought final.
Williams will displace her conqueror at the top of the world rankings on Monday but Azarenka is entitled to feel she is the top performer at present, having retained her Australian Open crown and now extended her 2013 record to 12-0.
Azarenka began the match well and broke to love in game three when Williams double-faulted, but the American broke back in game eight thanks to a beautiful forehand.
Azarenka then showed admirable grit to hold serve twice more and force a tie-break which proved critical.
The Belarussian claimed a 5-2 lead in the breaker, but Williams came up with a pair of big serves and found herself set point up when Azarenka double-faulted and then put a groundstroke long.
However, Williams squandered the set point, netting an attempted pass and, after Azarenka had unleashed a clean winner off a second serve, she clinched the tie-break 8-6 when Williams went wide.
Undaunted, Williams dominated the second set, breaking to love in game three and then adding an insurance break in game seven, aided by a pair of Azarenka double faults.
Williams served out the set without difficulty but found herself on the back foot at the start of set three, Azarenka breaking in game two.
Williams had a chance to break back in the very next game but Azarenka held on and found herself match point up at 5-2, only to go long.
Her 31-year-old opponent valiantly went on to hold serve but Azarenka made no mistake when she served for the match at 5-3, clinching victory when Williams put a return wide.
It was just Azarenka's second career victory over Williams, the American having won 11 of their previous 12 meetings.
Azarenka said: "It's amazing to have achieved what I have achieved.
"I just wanted to fight and give myself every opportunity to get back. I told myself 'you have to keep it together, you have to do something, otherwise Serena's on a roll'.
"I had to really step up my game and I'm glad that I could turn it around."