Kristof Vliegen beat Chris Guccione 6-4, 6-4, 6-4 on Sunday to give Belgium a spot in the quarterfinals of the Davis Cup and send 28-time champion Australia to the relegation round after a 3-2 win. Earlier, Lleyton Hewitt kept Australia alive by beating Olivier Rochus 6-2, 6-3, 6-7 (4), 3-6, 6-1. Belgium won both singles on Friday before Hewitt and Paul Hanley pulled one back in the doubles Saturday. One break in each of the three sets and a flawless serve was enough for Vliegen to beat Guccione. The big-hitting Australian, one of the tallest players on the men's circuit, was not at ease on the slow clay at Liege's Country Hall as his serve-and-volley game is more suited to hard surface. "This is phenomenal. It's the biggest moment of my career, a dream," Vliegen said. Hewitt, who lost in five sets to Vliegen in the opening singles, started his five-setter against Rochus in style, breaking the Belgian in the first game and taking the first set in just 30 minutes. Driven by a frenetic home crowd, Rochus stepped up a gear in the second set, breaking Hewitt in the second game with a series of brilliant returns, but the Australian - a former Wimbledon and US Open champion - broke back immediately then held his serve at love. Second set Rochus relied on his best shot, a heavily rotated backhand, but Hewitt covered the court well and took the lead after another break. He had seven aces in the second set. Hewitt continued to dominate in the third set in a battle of two baseliners with a minimum of net advances, but Rochus hit some quality shots down the line and managed three unlikely breaks before finally winning the set in a tiebreaker. The 34th-ranked Rochus capitalized on a growing number of unforced errors by Hewitt and took a quick 4-0 lead en route to an easy win in the fourth set. But the Australian regrouped remarkably in the final set, breaking Rochus twice and finally winning the match. "I though it was going to be tough match against Olivier, especially on surface like this. I started great, but he's a fighter," said Hewitt, who spent more than 10 hours on the court in three matches. Australia, a semifinalist last year, is the second most successful Davis Cup nation with 47 final appearances, including 28 titles, the last in 2003. The United States has 31 titles. Belgium is a newcomer in the top tier of men's team tennis after a three-year absence.