Sergiy was defeated 6-4, 6-4 by Oliver Rochus on Tuesday on the first round of the ATP Studena Croatia Open in Umag. The match lasted one hour and 45 minutes.
World No. 43 Stako wasted all five break point opportunities, while his opponent converted two of seven break point chances. Sergiy, who hit five aces, dropped to a 20-19 season record.
In men’s doubles first-round action, Stako and and his doubles partner Oliver Rochus lost 6-2, 6-4 to Italians Bolelli-Fognini.
Stako fell to No. 5 seed Gilles Simon of France 6-2, 6-1 in the second round at the bet-at-home Open on Tuesday. The match lasted 63 minutes.
Sergiy's serve let him down today. He won just 26 of 64 points on his serve and got broken seven times. He responded with only two breaks of serve. With this loss, he fell to 20-18 singles match record on the season.
It took Sergiy 65 minutes to defeat Maximo Gonzalez of Argentina 6-2, 6-3 on Monday at the bet-at-home Open, German Tennis Championships.
Stako won 71 per cent of his service points and converted four of five break point chances he created for his 20th singles match win of the year.
In the second round, he will play No. 5 seed Gilles Simon of France. They have played once before on the ATP World Tour and Simon won 6-3, 6-3 in Valencia, Spain, in 2010.
Argentine qualifier Federico del Bonis knocked out Sergiy 6-4, 6-3 in a second-round encounter at the Mercedes Cup in Stuttgart, Germany. The match lasted 78 minutes.
The 25 year old played his first tournament since reaching the second round at Wimbledon (lost to Ljubicic).
Stako won just five of 18 points on second serve and got broken five times. He managed to convert only two of 6 break point chances.
With this loss, Stako fell to a 19-17 season record.
His next stop is Hamburg, an ATP World Tour 500 event, which begins next week.
Stako fought his way to a marathon win over Czech Jaroslav Pospisil in round one at the Mercedes Cup. The match lasted two hours and 41 minutes.
The world No. 45 was forced to work hard to progress in Stuttgart on Monday, eventually winning 4-6, 6-2, 7-6(5), which was his 19th victory of the season.
He hit eight aces and won 73 per cent of service points. Besides, he broke his opponent twice and dropped serve only once.
Next up is Florian Mayer or a qualifier.