Usain Bolt sensationally defended his coveted title as the fastest man on the planet last night as he sprinted to glory in an Olympic record time of 9.63 seconds.In front of a global TV audience estimated at up to two billion, the 25 year-old Jamaican answered all the questions about his fitness and state of mind to retain his 100-metre sprint crown in what had been billed ‘the greatest’ race of London 2012 – and certainly the most anticipated.Known around the world as ‘Lightning Bolt’, he lived up to the legend to run the second-fastest time ever and beat his fellow Jamaican Yohan Blake, who claimed silver with a time of 9.75, and American Justin Gatlin, who won bronze in 9.79.Left trailing were American Tyson Gay and Bolt’s fellow Jamaican Asafa Powell.After the race, Bolt said: ‘I was happy when I went out in the first round, I felt I could do this.‘I was slightly worried about my start. It was not the best reaction in the world but I stopped worrying about it and executed it and it worked.‘I said it on the track, people can talk, all they can do is talk. When it comes to championships I bring it.‘I knew [the crowd] would be like this, I can feel that energy and I am extremely happy.’Speaking about his compatriot and training partner Blake, the champion said: ‘In training he always works hard and pushes me.‘I knew what I needed to do but I think he will do better next time. He is a major talent. He beat almost everybody and I know he will be more confident and do better next time.’Blake, who won silver, said: ‘Usain knows what it takes. He is a world beater and he is the fastest man in the world.‘But I got a medal in my first Olympic Games and a lot of that is down to Usain and our coach.’Bronze medallist Justin Gatlin, who won bronze in the men’s 100m final, told BBC Radio 5 live: ‘At this moment in time it was probably the dream race.‘It was a great race and I think there are even better ones to come.‘Usain Bolt has the best technique out there. I tried to hold on with my technique and I got back on the podium for the first time in 10 years.’Gatlin, the 2004 Olympic champion, was competing in London amid controversy after serving a four-year doping ban.He said: ‘It feels good, regardless of what I have gone through. I did this for the people who support me.‘This medal is for them and they pushed me when I didn’t want to push myself.’The race had been billed as the ‘hottest ticket’ of London 2012 with people paying prices of up to £725 to be among those in the stadium who could forever say ‘I was there’.In Britain alone the TV audience was expected to be about 15million – a quarter of all Britons – with theatres and cinemas putting on special screenings that had begun in time to the semi-finals earlier in the evening.Agencies