TOKYO–World number five Alexander Zverev won the biggest title of his career when he crushed Russian Karen Khachanov 6–3 6–1 on Sunday to win the men’s singles tennis gold medal at the Tokyo Olympics. The 24-year-old, who has yet to win a Grand Slam title, was in stunning form as he demolished Khachanov in 79 minutes to become the first German man to win a singles Olympic gold. Zverev, who secured a rare win over world number one Novak Djokovic in the semifinals, became only the second German to win Olympic singles tennis gold by matching Steffi Graff’s achievement at the 1988 Seoul Olympics. “There are only few people in this world who are happier than me at the moment,” Zverev said. “I can’t compare it because this is so much bigger than anything else in sports,” he told reporters. “A gold medal for me at the Olympics, the value …