Jordan Spieth has hailed the 'most incredible week' of his life after becoming the second youngest Masters winner of all time and  the first start-to-finish winner at Augusta in 39 years. Spieth held his nerve in Sunday's final round to keep control of the season's first major championship, matching Tiger Woods' record of an 18-under 270 and finishing four shots clear of the field. Speaking in Butler cabin as he prepared to receive his green jacket, the 21-year-old admitted that despite never giving up the lead, he was still a bag of nerves as he looked to hold off the attentions of two major champions in the form of Phil Mickelson and Justin Rose. Jordan Spieth has hailed the 'most incredible week' of his life after winning the Masters at Augusta . Spieth poses in his green jacket having held his nerve in Sunday's final round in a start-to-finish victory . 'It was very nerve-racking today,' Spieth said. 'I thought today might be a little easier than yesterday having played a round with the lead but it wasn't. I didn't sleep well last night, just got out here and got in a bit of rhythm and we were off. With two major champions behind I couldn't let up. 'It's the most incredible week of my life. This is as great as it gets in our sport, this is a dream come true for me. To shoot some low rounds and to see some putts go in out here and to hear those roars, it was remarkable.' Spieth was greeted by his family at the 18th green, with his father telling him to do a lap of honour for all the patrons round the 18th green. And the Texan said that it was the moment of seeing his loved ones where it finally dawned on him that he was going to win. Spieth hugs his father Shawn at the 18th green, and he admitted that seeing his family made things sink in . Of seeing his family and friends, Spieth said: 'at that point knew that it was going to be a done deal' Spieth hugs his grandfather Bob but later said that even then the excitement of winning hadn't fully kicked in . 'I saw my family and friends right behind the green, and at that point knew that it was going to be a done deal,' he said. 'To be honest, it didn't kick in there, it still hasn't kicked in. I'm still kind of in shock a little bit. 'I'm sure it'll settle in maybe a little later but it was really great to share that experience with my family who weren't there any of the couple of times I had one so to be at this one was special.' Asked what was next for him, having fulfilled a life-long ambition, Spieth said: 'I want to be like Bubba (Watson), I want to win two Masters! Spieth led from start to finish at Augusta, the first time that feat has been achieved in 39 years . The 21-year-old reacts after sinking his final putt to win the 2015 Masters Tournament on Sunday . 'I'm excited already to come back, I'm excited for the opportunity ahead this year to be the reigning Masters champion, I know that's going to carry a heavy weight with it and I hope to be ready for it.' Rose, who finished on 14-under had nothing but praise for the young champion. 'There's many players in the Tiger  era who have rued when Tiger won it by 15 or 12. Ernie Els, for example, could have won a bunch more major championships if it wasn't for one guy. 'Jordan seems to have that same quality right now and he's very comfortable playing with a lead. A 14 under round here... I'll take that every year and take my chances.' Justin Rose (left) finished on 14-under and had nothing but praise for the new young champion .
Jordan Spieth became the second youngest Masters winner of all time .
His 18-under round was the joint-record and he led from start to finish .
Spieth hailed the week at Augusta as the most incredible of his life .
21-year-old admitted that the accolade had not quite sunk in yet .
Justin Rose praised Spieth, saying he showed comfort playing with a lead .