Victoria Azarenka upset world number one Serena Williams to claim the BNP Paribas Open title in Indian Wells.
The 2012 champion took advantage of the American's wayward serve and erratic ground shots to earn a 6-4 6-4 win.
In the men's final, Serbia's Novak Djokovic beat Milos Raonic of Canada 6-2 6-0 to secure his 27th Masters title.
Before Sunday's matches, tournament chief Raymond Moore caused controversy when he claimed the women's tour "ride on the coat-tails of the men".
Williams' slow start
Williams was hoping to be the first female player to win three Indian Wells titles after taking a self-imposed 14-year exile from the event amidst allegations of racial abuse from fans after sister Venus withdrew minutes before their semi-final in 2001.
The emotion of the occasion was obvious in a tearful speech after the match when she told the crowd that their cheers "meant a lot to me".
She had made a nervous start to the match, dropping an opening service game that included three double faults.
Azarenka showed composure and steely defence under a barrage of fierce hitting from Williams, who committed 33 unforced errors.
The two-time Australian Open champion served out the first set to love as she established control.
Azarenka holds off Williams fightback
Williams' troubles intensified when she dropped her first service game of the second, then failed to take any of four break points in the next game to trail 2-0.
When she dropped serve again, Williams could not hide her frustration and was given a code violation and then a point penalty after smashing one racket and another when it was still in its wrapper.
But Williams is never more dangerous than when she is down and finally converted her first break point at the 10th attempt for 5-3, then held her serve to raise the pressure on Azarenka.
It looked like Williams would level at 5-5 but missed two more break points while Azarenka held her nerve to take her 19th WTA Tour title, which means she will be back in the top 10 of the world rankings on Monday.
It was only the fourth time the 26-year-old Belarusian had beaten 34-year-old Williams in 21 meetings.
'The WTA ride on coat-tails of the men'
During a Sunday morning news conference before the finals, Indian Wells Tennis Garden CEO Raymond Moore said that the WTA Tour was "very, very lucky" because it "rides on the coat-tails of the men".
"If I was a lady player, I'd go down every night on my knees and thank God that Roger Federer and Rafa Nadal were born, because they have carried this sport. They really have," Moore said.
Williams reacted angrily to Moore's "offensive" statement, which he later apologised for, calling the remarks "mistaken and very, very, very inaccurate".
She added: "If I could tell you every day how many people say they don't watch tennis unless they're watching myself or my sister, I couldn't even bring up that number."
Billie Jean King, who co-founded the WTA Tour and won 12 Grand Slam singles titles, tweeted: "Disappointed in Raymond Moore comments. He is wrong on so many levels. Every player, especially the top players, contribute to our success."
Djokovic continues domination
Tournament director Moore was on safer ground when he joked about renaming the venue "the Novak Djokovic centre court" after the world number one secured his fifth title at Indian Wells.
Djokovic was barely tested by Raonic, 25, who seemed troubled by a lower back injury that affected his serve and forced him to take a seven-minute injury break between sets.
The Canadian made 27 unforced errors in the 14 games, compared to Djokovic's four, and won just 10% of his second serves during a match that lasted one hour and 17 minutes.
The victory, the 62nd of his career, sees the 28-year-old draw level with Roger Federer on 27 Masters 1000 tournament victories, and he has a chance to go past the Swiss with victory at the Miami Masters, which starts on Wednesday.
"I think it is the best I played all week," Djokovic said afterwards.
"Milos' injury allowed me to move him around the baseline, his first serve problems allowed me to step in and dictate the play, and I was on top of his every second serve."