Despite the loss, Sitak is projected to move to a career high of 38 in the rankings which come out after the French Open. He will take plenty of confidence into the grass court season.
Meanwhile, top New Zealand singles player Rubin Statham has lost in the second round of qualifying at the ATP Challenger tournament in Shymkent in Kazakhstan. Statham has been beaten 6-2, 7-5 by Russian Mikhail Elgin and now turns his attention to the doubles where he will play with Chinese Taipei player Chen Ti against India's Arjun Kadhe and Kazakhstan's Denis Yevseyev in the first round.
New Zealand women's player Erin Routliffe has won through to the final round of qualifying at the latest ITF Futures tournament in Hua Hin Thailand.
The 23 year old has beaten Australian Maree Casey 6-2 6-3 and will face India's Ramya Natarajan for a place in the main draw. Routliffe and Mexican partner Victoria Rodriguez are the top seeds for the doubles having captured the title together at the previous tournament last week.
They have been drawn against a Belgian and Russian in the first round.
And fresh from winning his first ITF Futures doubles title in China, Rhett Purcell plays Japanese player Kaito Uesugi in the first round of the singles at a Futures tournament in Japan. He is teaming up with Japanese player Issei Okamura for the doubles.