Canadian wildcard Bianca Andreescu was in disbelief after winning the Indian Wells Open, describing her victory as a "Cinderella story".
The 18-year-old Canadian fought off exhaustion and held her nerve to triumph 6-4 3-6 6-4 over the three-time Grand Slam champion, becoming the first wildcard victor of the prestigious event.
Kerber, a former world number one who had slipped to eighth in the rankings as she searched for a first title since she won Wimbledon previous year, was up a break in the third set when Andreescu powered through fatigue and cramping to seize the victory.
- Andreescu told the press after winning her first WTA title.
Leading 2-1 in the third, Andreescu took a medical timeout and had a trainer massage her tight right shoulder and arm.
Andreescu won't get to enjoy her success for very long though, she's already set to play 70th ranked Romanian Irina-Camelia Begu in the first round of the Miami Masters 1000 tournament early this week.
"At the end I was not able to take my chances, but she did", Kerber said. "So it's insane what a year can do", Andreescu told reporters after her 6-4 3-6 6-4 win.
The victory vaulted Andreescu to a dizzyingly high ranking of 24th in the world, up 128 places since last December. He just needed to convince her that she had the fight, that she had the strength, that she had to go for every point.
She broke Kerber in the next game, taking a 15-30 lead with a lovely drop shot-lob combination, and giving herself a break point with an overhead victor before converting with another forehand victor to launch a run of three straight games for a 5-3 lead. The Canadian hit a phenomenal drop shot victor to set up break point, but Kerber dug in the next few points to hold for 2-1. "And now to be able to have my name in front of so many awesome champions is, it means the world to me", said Andreescu.More news: Boeing: French investigators find crash 'similarities'
Kerber used all her experience to fight off three match points, and when the German took advantage of an Andreescu mistake to break back, it seemed that the momentum had once again swung her way.
Andreescu had three championship points but couldn't pull the trigger.
Nerves appeared to get to Andreescu near the end, when Kerber saved three match points behind some stout defence.
Midway through their chat, Andreescu extended the fingers on her left hand, tossed her energy drink in her bag and made the emphatic "I want this so bad!" declaration.
"You never know what next week brings".
Thiem trailed 4-3 and 5-4 in the third set before breaking Federer with a forehand victor to go up 6-5.
But when the moment arrived for real, she said, it was "surreal".
Not being 100 percent fit is nothing new for Andreescu.