Bulli's Ryan Gregson will compete for the national 5000m title at the IAAF World Athletics Tour meet at Melbourne Olympic Park tonight.Gregson, 18, smashed the Australian under 20 1500m record at the Sydney Track Classic last Saturday night.Gregson's short-term goal is the IAAF World Junior Cross-Country Championships over an 8km course in Amman, Jordan, on March 28 and his long-range focus is to qualify for the IAAF World Championships at Berlin, Germany, in August.All the hard cross-training work in the pool and on a bike while recovering from a stress fracture to his right fibula last November is paying dividends for Gregson.As part of his lead up to the world junior championships, he will also compete in a 3000m race at Christchurch, New Zealand next week.The world junior cross-country race is over an 8km course and Gregson believes the 5000m in Melbourne may suit him more than the 1500m did in Sydney where he clocked 3min 37.24sec to finish third behind Bahrain's Yusuf Saad Kamel (3:36.72) and Victorian Collis Birmingham (3:37.01) last weekend.In breaking Mike Hillardt's Australian under 20 record time of 3:39.67, Gregson improved on his previous personal best time by almost 4sec."My training has been more for an 8km race, so to come out and run a good race over a shorter distance has given me a lot of confidence for Melbourne," Gregson said yesterday."I didn't think I'd be in that kind of shape so it was a real surprise."I thought maybe I might just sneak under the record, but to run the time I did and to finish in the top three at my age was great."Unlike in Sydney, there is a national title at stake in Melbourne."Birmingham, who ran the 5000m at the Beijing Olympic Games, will start favourite but it shapes up as an open competition after him.In this event, Gregson is concentrating on a gold medal for winning an Australian title rather than setting a record time in what is expected to be windy conditions.The world's second fastest man, Asafa Powell, and reigning Olympic pole vault champion, Steve Hooker, are aiming to make history at Olympic Park. Powell wants to become the first man to better 10sec on Victorian soil. He warmed up with a personal best of 45.94 in the unfamiliar 400m last weekend in Sydney. After a remarkable recent run of success in the US and Europe, Melbourne-born Hooker is targeting a 6m clearance on home soil against a world-class pole vault field including fellow 6m men Paul Burgess, Tim Mack and Olympic silver medallist Yevgeny Lukyanenko.