World No. 1 Roger Federer extended his season win streak to 17 matches, booking his spot in the Indian Wells Masters final by rallying past Borna Coric 5-7, 6-4, 6-4 on Saturday.The Swiss superstar survived a stern test from world number 49 Coric but managed to hold on for a 17-0 record this year.He surpassed his prior career-best calendar year start in 2006 when he opened with 16 wins."It took a while to get the record," Federer said. "But I'm happy. It was just a fighting match, It didn't come easy, so I had to go get it. I got a little bit lucky. I hung tough and put a lot of effort into it to get the record," he added.Federer said it's time to focus on finals now. "The focus has to be the finals right now. But it's nice to get off to a good start this year, and I hope I can play well again tomorrow."The defending champion will be aiming for a record sixth Indian Wells title when he squares off against world number eight Juan Martin Del Potro in Sunday's championship match.The 36-year-old Federer said he had to draw on every ounce of experience and mental toughness to pull out the match."Margins are slim at the top of the game," he said. "And I have been there so many times. You just hope to take the right decisions along the way, and then it ends up falling your way.""But for that you need to have a very positive mindset. You need to be match-tough, you need to be confident, have experience, and I think I have a bit of all of that right now."Federer clinched the match when Coric hit a shot wide. The ball was called out but Coric challenged and after the video review the original call was confirmed.