LONDON – The Lightning Bolt, it's back, baby.  Usain Bolt, who set the track world on fire four years ago with a dominant Olympic performance in Beijing, looks like he's going to do it again in London.  Bolt, 25, the Jamaican world record-holder and defending Olympic champion, exploded down the track at London's Olympic Stadium and won the gold medal in the 100 meters Sunday night in a blazing time of 9.63 seconds.  The mark broke his Olympic record set in Beijing — 9.69 — and was just .05 seconds off the world record of 9.58 he set at the 2009 world championships.  So, was Bolt bluffing us this year? He had suddenly become vulnerable, losing in both the 100 and the 200 to 22-year-old training partner Yohan Blake at the Jamaican Olympic trials.  Bolt's starts were sluggish. His back was an issue. His hamstring was an issue. Some critics even said his partying might be an issue.  Sunday night, there were no issues.  He got out of the blocks fine — not great, but fine — and found himself, in Lane 7, slightly behind U.S. veteran Justin Gatlin, a sensational starter, in Lane 6.  But as soon as he got his incomparably long stride going, the 6-5 Bolt caught Gatlin, passing him and everyone else.  "Bolt was Bolt," Gatlin said. "He's a great runner. He's 6-5. That adds to his success. You have to try to neutralize that."  It was an eye-opening, jaw-dropping performance after so many months of speculation that the Bolt Era in track might be in decline.  "He's an unbelievable sprinter," said Trinidad and Tobago sprinter Richard Thompson, who was seventh. "The entire world thinks he's unbeatable and right now he is."  Blake, in Lane 2, finished in 9.75 to claim the silver medal. Gatlin, 30, the 2004 Olympic champion who served a four-year doping suspension that ended in 2010, finished in 9.79 for the bronze.  "It means so much to me," Gatlin said. "It was a great race. One for the history books. I'm just glad to be a part of it."  Tyson Gay, 29, the second-fastest man in the world by virtue of his 9.69 in 2009, was trying to race against the short clock and a long clock — he was coming back from 2011 hip surgery. He summoned a big effort — a season-best 9.8 — but in this company, on this night, that was good for only fourth.  They call fourth the cruelest finish at the Olympics, and Gay was crying as he struggled to complete sentences to reporters in the interview area.  "I don't think I could go back and do nothing else," he said. "I feel like I ran with the field. I just came up short. That's all I did."  Team USA's Ryan Bailey, with a person-best 9.88, was fifth.  Seven of eight runners finished under 9.98 seconds, with Jamaica's Asafa Powell, a former world record-holder, pulling up and finishing in 11.99 seconds.  Much had been made about the possibility of bad weather preventing fast times on the Olympic Stadium track.  But at race time Sunday night, just before 10 p.m. London time, when the fastest men in the world lined up to see who is fastest, the weather was perfect.  The anticipation hardly could have been greater, for a lot of reasons.  The main question was whether we would see the Beijing Bolt again, or the lesser version that had been on display this season  In Beijing, Bolt ran three races and set three world records — 9.69 in the 100, 19.30 in the 200, plus a third world record on Jamaica's winning 4x100 relay team.  The next year, at the 2009 world championships in Berlin, Bolt lowered those marks to 9.58 in the 100 and 19.19 in the 200.  And there those records have remained.  In 2010, Bolt's fastest time was 9.82. Last year, his fastest was 9.76, and he was disqualified for a false start in the 100 meters at the world championships in Daegu, South Korea.  This season, 9.76 again had been his fastest time, and he had suffered the two losses to Blake.  People have wondered whether he was 100% healthy. He was bothered earlier this year by a back issue that morphed into a tender hamstring.  Also, people have wondered whether Bolt was worried about false starting, unable to shake his mishap in Daegu.  He has said that's not the case, and he has shrugged off criticism of his start with a rather unusual explanation.  "We have come to the conclusion that back in the day, I was never a good starter, and I'm never going to be a great starter," Bolt said a few days before the Games, referring to himself and his coach, Glen Mills. "So I should just get past that and focus on just running. I'm not worried about the start. It's all about execution and getting it right at the end of the race."  But there was still this to wonder: What exactly is getting it right for Bolt now, at age 25, four years after electrifying the Beijing Olympics with his prancing and preening but most of all his explosive speed?  Was another 9.76 getting it right?  Did he have another 9.5 again? Or even a 9.6?  In Round 1 in London Saturday, Bolt stumbled out of the blocks — another sluggish start — and lumbered to the line in 10.09 seconds.  During introductions for his semifinal heat Sunday evening, he struck a boxing pose and threw a right and a left.  Then he looked as comfortable as could be, starting pretty well, driving through the halfway point as an Olympic champion would, and then easing up at the finish with a big lead. His time — 9.87 — was impressive for how easily he took the finish.  Then — wow! The old Bolt, back, accelerating away from the field and into history, the first repeat gold medalist in the 100 since Carl Lewis in 1984 and '88 — the '88 gold coming after Ben Johnson's disqualification for doping.  Bolt will be back in the 200 meters, and he is likely to be back for another Olympics in 2016. He is just 25, after all.  This might have been the end of the Olympic road for Gatlin, who will be 34 in 2016, and Gay, who will be 33.
Bolt was the big story in track and field coming into the London Games. He still is after sprinting to an Olympic record.