SUNNY Poon Yat-sing led underdogs Perrier to a 5-1 victory over Express One at the Hong Kong Squash Centre yesterday to maintain their unbeaten run in the U2 Premier League after four rounds. Poon, who has been receiving private coaching from Peter Hill, showed the benefit of the tutoring by the Singaporean ace with his first win over national squad teammate Andrew Shum Siu-chung. The Perrier number one came back from the brink of defeat by saving two match balls and then went on to outlast Shum 15-7, 2-15, 10-15, 15-14, 15-10. 'We have been rivals since our schooldays and it took me almost 10 years to post this first win over him,' said a delighted Poon. Au Chun-tat and Dushyant Singh won their matches to give Perrier five points while Wong Wai-hang saved Express One from a whitewash with a win over Fayyaz Mohammad. Perrier head the standings with 20 points, four ahead of second-placed Fuji who edged Express Two 4-2. Mohammad Saddiq and John Choi Wing-yiu were the winners for Fuji while Chan Siu-sing and Allen Ngan Wai-ming clinched the points for Express Two. Rubicon leapt from fifth to third with 12 points after scoring a 5-1 win over trouble-torn defending champions Hong Kong Football Club, who lost their sponsor days before the league kicked off last month. They are in more trouble because number one Peter Hill was injured during his match against Faheem Khan and retired in the second game.