WIMBLEDON, England -- Ukraine's Andrei Medvedev and his Russian friend Yevgeny Kafelnikov proved there is more than one way to win on grass when they eased through to the third round of Wimbledon. But 15th-seeded Kafelnikov, 20, fell Friday in the fourth round to Daniel Vacek of the Czech Republic, 4-6, 7-5, 6-4, 3-6, 6-4.A day earlier Kafelnikov, 20, who has been nicknamed Kalashnikov for his explosive tennis, had looked invincible as he destroyed Germany's Karsten Braasch 6-1, 6-1, 6-3 with an aggressive serve-and-volley game. On Thursday, ninth-seed Medvedev hung back on the baseline for much of his clash with Slava Dosedel of the Czech Republic and relied on his groundstrokes to take him to a 3-6, 7-5, 6-1, 6-4 victory. The rising star of Russian tennis, Kafelnikov scored wins over former Wimbledon winners Andre Agassi and Michael Stich in Monte Carlo earlier this year before being stopped in his tracks by close friend and gambling partner Medvedev. The two were regular visitors to the principality's famous casino, although they admitted they were less successful on the roulette table than on the tennis court. Medvedev, 19, has delighted crowds with his mischievous grin and keen sense of humor.He said after his win over Dosedel that he had been forced to play from the back of the court by a nagging thigh injury which prevented him charging into the net. Trailing by a set to love and a game down in the second set, Medvedev was treated to a leg massage and an aspirin by his trainer. The remedy appeared to work and he went on to take three sets in a row to set up his next game, a third-round clash with Australia's Richard Fromberg. "I proved to myself you don't have to serve and volley to win the points on grass," Medvedev said. But the Ukrainian was modest about his chances at the All England Club. "This is not yet a tournament I think I can win," he said.