ROTTERDAM, Netherlands — Roger Federer delivered a crushing 6-1, 6-2 defeat of Ruben Bemelmans in just 47 minutes Wednesday as the Swiss star moved just two wins away from becoming the sport’s oldest world No. 1. The 36-year-old top seed, a two-time champion at the Dutch indoor event, needs to reach the semifinals to take back the No. 1 spot from Rafael Nadal. With two more victories, Federer would become the oldest man by three years to hold the top position in the rankings. “It’s very surprising how good things went today,” Federer said. “The key is to start well, put him under pressure. “I wanted to make him think he had to do something special to beat me. I did well there, I felt good, I’m healthy and I’m confident. It was a great first round for me.” Federer gave no quarter as he raced to a 5-0 lead, with the out-matched Bemelmans winning his first game after 16 minutes. The outcome was never in doubt as Federer dominated with six aces and four service breaks, winning an impressive 21 of 23 first-serve points in the demolition. The 20-time Grand Slam champion Thursday takes on German Philipp Kohlschreiber, against whom he stands 12-0 in career meetings. “You always prefer to play the guy whose game you know,” Federer said. “You know his patterns, it’s nice to play someone like that, you know what to expect. “My start will be crucial, I need to stay focused all the way. Any lapses can get you into trouble.” Third seed Alexander Zverev fell in an upset to qualifying lucky loser Andreas Seppi of Italy, 6-4, 6-3 in the second round to open up Federer’s half of the draw. Grigor Dimitrov and David Goffin, the duo who faced off in last year’s season-ending ATP Finals, both advanced with straight-sets wins. Second seed Dimitrov, who beat Belgian fourth seed Goffin in the London final last November, had to fight back in the second set to defeat Japan’s Yuichi Sugita 6-4, 7-6 (7/5) in their first-round encounter. Goffin made light work of veteran Spaniard Feliciano Lopez, cruising through 6-1, 6-3 to reach the quarterfinals. Dimitrov won the opening set against Sugita but fell behind a break in the second before leveling for 5-all. As the set went into a tie-break, the Bulgarian surged ahead as he took a 5-2 lead but had to hold off his opponent as Sugita clawed back to within a point of leveling. Dimitrov then sent a forehand into the corner to earn a pair of match points and advanced on his second with a service winner to end the resistance of the 41st-ranked Sugita. “It was my first match in three weeks, and you’re always a little rusty,” said Dimitrov who has been dealing with a sore shoulder in recent weeks. “I was trying to find rhythm. I faced a quality player and I’m happy with how things went for me today — I was pain-free in my shoulder.” Last weekend’s Montpellier champion Lucas Pouille exited in his opening match, losing 7-5, 6-4 to Andrey Rublev. The Russian was joined in the second round at the Ahoy Arena by Pierre-Hugues Herbert of France, who advanced after just 15 minutes when compatriot Richard Gasquet, the Montpellier finalist, retired with a groin injury trailing 3-1. Pouille lost in 93 minutes, hitting a dozen aces in defeat but losing serve four times. The 34th-ranked Rublev owns his only career title from Umag last summer on clay. Herbert will play Russian Daniil Medvedev in the second round. Robin Haase won an all-Dutch affair over Thiemo de Bakker 6-2, 6-2. Sharapova, Keys pull out Former world No. 1 Maria Sharapova and US Open finalist Madison Keys have pulled out of next week’s Dubai Duty Free Tennis Championships, the tournament organizers said Thursday. Five-time Grand Slam winner Sharapova, who had a accepted a wildcard to make her first appearance at the tournament since 2006, decided to withdraw citing a forearm strain. American world number 14 Keys, who was expected to make her Dubai debut, has withdrawn due to illness. The tournament begins Monday with world No. 2 Simona Halep set to lead the field alongside defending champion Elina Svitolina. — Agencies