Juan Martin Del Potro
Mar 18, 2018; Indian Wells, CA, USA; Juan Martin Del Potro poises with the championship trophy after defeating Roger Federer (not pictured) in the men's finals in the BNP Paribas Open at the Indian Wells Tennis Garden. USA TODAY Sports / Jayne Kamin-Oncea

World No. 1 Roger Federer lavished praise on long-time nemesis Juan Martin del Potro after their hard-fought battle during Sunday's Indian Wells final. After capturing the 2018 Australian Open, Federer claimed his career 97th ATP Tour victory at the Netherlands last month to make his best-ever start to a new season.

But the Swiss Master's momentum was ended by del Potro, who became the first Argentine to win a top-tier Masters series event. Del Potro, who defeated Federer in last year's US Open semi-final, saved three match points in the deciding set before the Swiss legend struggled to serve out.

"I'm so happy to win a title like this. I lost many finals in Masters 1000s but today was the day for me. I played unbelievable tennis, almost three hours, and beating Roger for the first time this year, that means a lot to me," Del Potro said before dedicating his first ATP Masters 1000 title to his beloved dog Cesar, who recently passed away.

"I cannot believe this moment. I always think about what I did in the past, trying to fix my wrist problems. I did, I'm playing tennis again and winning titles so I have a lot of things to celebrate and this trophy is one of them," del Potro added after winning the 2018 BNP Paribas Open.

While expressing frustration at his inability to capitalise on key moments, Federer praised del Potro for holding his nerves and getting to finish line. "I feel frustrated, you know, that I let an opportunity like this go by. (Having said that), Juan Martin well played today. It was a tough match, but well done you deserve it. There was not much between us, but you deserved it. Well done and enjoy the moment," Federer said during the post-tournament presentation ceremony.

After the Indian Wells event, Federer will now shift his attention to the 2018 Miami Open at Key Biscayne, Florida, United States. A year ago, the Swiss player pulled off the "Sunshine Double" in Florida by claiming both the Indian Wells and the Miami Open titles. With Rafael Nadal set to miss the Key Biscayne event, Federer is expected to stay as the World No. 1 for the foreseeable future.