ATHENS, Aug 6: Michael Johnson played the role of Superman on and off the track. He also cashed in his `wild card' in proving that he is still the world's best 400-metre runner.First, the irrepressible Johnson won his third straight 400m title at the World Championships on Tuesday night. Then, he was thrown a Superman T-shirt by a fan from the crowd estimated at more than 70,000 in Olympic Stadium and carried it around the track in a proud victory lap.Johnson achieved one of his most satisfying victories in 44.12 seconds, the third-fastest time in the world this year, despite a cramp on the inside of his left leg. It was the same area he had injured during his 150-metre race against Donovan Bailey on June 1.``I felt the cramp coming around the curve,'' said Johnson, who trailed Britain's Iwan Thomas and Uganda's Davis Kamoga at that point.Nevertheless, the muscular Johnson was able to power his way clear of the field with about 60 metres remaining and went on to win by more than three metres.Afterward, he raised his hands to the crowd and was warmly embraced by American Tyree Washington, who finished third, behind Kamoga. He also was given two ice packs and some ointment for his injury.``I'm pleased to be back and to be healthy,'' Johnson said, momentarily forgetting about the cramp. ``I felt confident. Nothing was difficult for me this week.''Johnson's emotional victory overshadowed two historic developments on the Championships' fourth day of competition.Marius Corbett, who was not ranked in the world's top 10 in the men's javelin prior to the Championships, became South Africa's first-ever gold medalist with an African-record throw of 88.40 metres.And Sally Barsosio, 19, became the first Kenyan woman to win a gold medal at either the World Championships or the Olympics, taking the women's 10,000 metres in a world junior record 31:32.92.In the other finals, Cuba's Ivan Pedroso, the three-time world indoor champion in the men's long jump, took his second straight outdoor title at 8.42 metres, and Carla Sacramento of Portugal earned her first major title, winning the women's 1,500 with her season's best of 4:04.24.Kenya swept the medals of the 3,000 metre steeplechase with Wilson Boit Kipketer beating three-time champion Moses Kiptanui and Bernard Barmasai.Kipketer upset the odds when he swept past Kiptanui to win in 8 minutes 05.84 seconds, edging Kiptanui and Barmasai, who finished in the same time, by .20 seconds.Earlier in the meet, Washington had criticised Johnson for not having ``heart''.After the race, Washington reversed his stance. ``He has it in his heart now. I tried to go out and see if I could beat him, but the last 30 or 40 metres, he got me. He wanted to prove something today and he did.''Corbett's unexpected gold in the javelin came one day after Llewellyn Herbert won South Africa's first medal at the World Championships by finishing second in the men's 400 hurdles.``I never thought about the gold,'' said Corbett, a fourth-year physical education student in Potchestroon, South Africa. ``Maybe fourth or fifth. Yet then I threw a personal best by five metres.''Corbett's road to the title was eased when the Czech Republic's Jan Zelezny, the two-time defending world champion, two-time Olympic gold medalist and world record-holder, failed to qualify for the final.Barsosio, the youngest ever World Championship medalist with a bronze in 1993 at age 15, beat defending champion and Olympic titlist Fernanda Ribeiro by 40 metres.Barsosio, known for her rough tactics on the track, steered clear of trouble this time and swept past the tiring Ribeiro with 1,400 metres remaining.Pedroso's winning jump came on his first attempt, and after that, he had only one more legal jump, fouling four times.