Zagreb - Sixth-seeded Mikhail Youzhny of Russia has swept past Sergiy Stakhovsky of Ukraine 6-1, 6-2 to reach the Zagreb Indoors quarter-finals on Wednesday.
Youzhny won four games in a row but was broken when serving for the first set.
He broke back to seal the first set and moved to 5-0 in the second.
"It was much tougher than it seems," Youzhny insisted. "I had to save two break points early into the match and every game was a battle."
Youzhny defeated Stakhovsky the last time they met in Zagreb three years ago, and leads their head-to-head 4-1.
Eighth-seeded Marcel Granollers of Spain won his first-round match, beating Jurgen Melzer of Austria 6-2, 7-6 (3). Granollers faced no break point and won 88% of points on first serve.
The Spaniard won four games in a row in the first set, moving from 2-2 to 6-2. Both players held serve in the second set.
In other first round matches, James Ward from Great Britain defeated Croatian wild card Antonio Veic 6-2, 6-4, while Igor Sijsling from the Netherlands beat Canadian qualifier Frank Dancevic, 6-4, 7-5.