world number one janx CER made quick work of 20-year-old American Alex Michaelson in the second round of the US Open the Italian prevailing 64 60 62 on Thursday in New York CER who also defeated Michaelson during the Cincinnati open earlier this month notched his 50th match win of the season and his 30th on hardc courts most on the ATP Tour sinner saved three of five break points while converting eight of six 16 chances to break Michaelson Serv van route to victory in a tidy 1 hour 39 minutes he capitalized on Michaelson's 32 unforced errors I am very happy to get through he is a very tough opponent sinner said postmatch we had a match in Cincinnati one week ago so I knew a little what to expect s's third round opponent will be Australian Christopher okell who beat Italian qualifier mashi AB baluchi 63 6496 63 it wasn't as breezy for other top seeds on Thursday Australia's Jordan Thompson unseated but trank 32nd in the world rolled past number seven seed Hubert her Cates of Poland 76 2 61 75 Thompson hit 13 Aces to just two double faults and 142 of his 51 First Service points 82.4% Thomas mckack of the Czech Republic toppled number 16 seed Sebastian and C of the US 64 62 64 to reach the third round of the US Open for the first time it was pretty difficult I think I was playing a solid match so was sebbi at the beginning maak said at the beginning of the third set I noticed he was struggling shaking out his hand but he was still fighting so much and playing like he wasn't in pain so I had to be really focused on my tennis number 30 seed Mato arnaldi of Italy beat Russia's Roman in 62 64 64 11 other matches were scheduled for Thursday including number 5c Danel medev of Russia facing hungary's Fabian morassin and number three Carlos sarz of Spain facing B Vanda an's help of the Netherlands at