LOS ANGELES • Roger Federer had been aiming for a record sixth Indian Wells Masters tennis title to move one step closer to Jimmy Connors' all-time record of 109 in the men's game.
But instead, it was Dominic Thiem who reached two milestones after claiming his first ATP Masters 1000 crown in the Californian desert.
The Swiss legend was unable to win his 101st title, losing to the Austrian 3-6, 6-3, 7-5 in the final on Sunday.
The latter reached the French Open final last year, but his first victory over Federer on hard courts to move ahead 3-2 in career meetings is his most significant.
He earned it - just barely - by putting his baseline power and flashy one-handed backhand to work, breaking his opponent at 5-5 in the third set before holding firm.
Describing the upset as "unreal", Thiem, who is the first Austrian to win a Masters 1000 title since Thomas Muster at Miami in 1997, admitted he was only able to beat Federer by "playing double-good".
The 25-year-old said post-match: "I came from a really bad form in all categories and now, I'm the champion of Indian Wells. It feels not real at all.
"It's tough against Roger, Rafa (Nadal), Novak (Djokovic). Because you have to beat not only the player, but somehow, also the great aura they all have, all these titles they have won."
He also cracked a joke at the magnitude of his achievement in comparison to the 20-time Grand Slam winner, saying "it's not my right to congratulate you, you have 88 more titles than me".
Thiem, who yesterday jumped four places to world No. 4, added: "It is such a pleasure to compete with you, to learn so much from you, and to play with one of the biggest legends of all time."
Federer remained gracious in defeat after falling short at the final hurdle for the second straight time - last year, he squandered three championship points in a loss to Argentinian Juan Martin del Potro.
Coming into the contest, the 37-year-old had won 20 straight finals when taking the opening set, but this time, he "just came up against somebody, who on the day, was a bit better when it really mattered".
The fifth-ranked Swiss told reporters: "I had my chances, was in the points. That's why I'm not too disappointed.
"It's been a great week for me, even though it didn't work out. I just got my 100th (career title) in Dubai and I had a good week here. Really, there is no reason to get down. Plus, there is more to look forward to in Miami.
"Congratulations to Dominic - wonderful week and great play at the end. You deserved it."
Both players will now head to the Miami Open, where Thiem will be hoping to complete the "Sunshine Double".
AGENCE FRANCE-PRESSE, NY TIMES, REUTERS