Miami - Serena
Williams snapped out of her early doldrums to roar to a record seventh
Miami WTA title on Saturday with a 7-5, 6-1 win over China's Li Na.
In a battle of the world's top two players, the US world number one took her tally of WTA titles to 59 - including 17 Grand Slam triumphs.
She added a second trophy in 2014 to the one she lifted in Brisbane in January and joined Martina Navratilova, Steffi Graf and Chris Evert as the only women in the Open era to win the same title seven or more times.
"I was actually super-excited at the end," said Williams, who already owned the most WTA titles in the combined men's and women's event but had shared the overall record of six trophies with Andre Agassi.
"Obviously I wanted to have the most titles here," added Williams, who lives in Miami and first played the tournament as a 16-year-old.
"I guess that I've grown up coming to this tournament as a kid, watching so many players, and to be one of those players now is really, really awesome for me," she said.
Williams' ebullient celebration was a sharp contrast to her somnambulant start, during which Australian Open champion Li powered to a 5-2 lead with Williams surrendering a second service break with a double fault in the seventh game.
The seriousness of her situation seemed to wake Williams up. She won the next five games to take the set, saving a set point in the 10th game and hanging on to break Li in a 12th game that went to deuce six times.
"I really thought I could do better," Williams said of her thoughts at falling 5-2 down. "My serve, percentage was super, super low,and I thought, 'OK, I can serve a little better, and I know I can return better. I'm practicing all these years and I have a good return. I need to start doing it.'"
Although she delivered only three aces in a match that lasted just under two hours, Williams' serve did steadily improve as the match wore on, as did the power and precision of her returns.
She seized a 5-1 lead in the second set with a fierce backhand winner on her fifth break point of the game and wrapped up the contest on her first match point.
Although the match turned so dramatically, with Williams winning 11 of the last 12 games, Li had little to reproach herself for as she continued to battle even as Williams inexorably pulled away.
"I don't think I was playing bad," Li said. "Maybe she just started playing a little bit better after 5-2 down.
"I think it was a pretty good match."
Li, who won her second Grand Slam title at the Australian Open in January, has now lost 10 straight matches against Williams.
Her only victory in their 12 meetings was back in 2008, but Williams said she always feels challenged by Li.
"We just have this never give up fight," Williams said adding that she also feels a special connection with Li because they are both still battling on the WTA tour at 32 years of age.
"It just goes to show that you can still shine at any age," Williams said.