Dominic Thiem described beating Roger Federer to claim the biggest title of his career at the Indian Wells Masters as being "as nice as a grand slam".

Thiem fought back from a set down to defeat the 20-time major champion 3-6 6-3 7-5 in California on Sunday.

The Austrian, up to fourth in the rankings after securing his maiden Masters title, was pinching himself after toppling Federer for a third time in five encounters with the Swiss legend.

"It's unreal," said Thiem. "It's a pleasure to compete against Roger in this great final. I lost my last two Masters 1000 finals, but I won this one and it feels as nice as a grand slam.

"It was a great week and I think also a very good final. Just amazing that I got here, [it is] my first really big title.

"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."

Thiem was particularly pleased with the way he hung in there under pressure to get the better of Federer.

The 2018 French Open runner-up added: "I was in the zone the whole match. I had to get used to Roger's game. In the first set he was playing amazing.

"It was completely different from my opponents before him. I was struggling to work my way into the match. I had to fight to save those break points early in the second set.

"It was a very good match until the end and I had to fight to serve it out."