BUENOS AIRES • Japanese top seed Kei Nishikori lost a sixth successive final on Sunday when he was defeated by Ukraine's Alexandr Dolgopolov 7-6 (7-4), 6-4 in the Buenos Aires clay-court title match.
The world No. 5 had already lost in the Brisbane final in January to Grigor Dimitrov which followed 2016 defeats in tournament deciders in Basel (against Marin Cilic), Toronto (Novak Djokovic), Barcelona (Rafael Nadal) and Miami (Djokovic).
"I'm happy to be in the final. Unfortunately I lost today, but Alex played better than me. I didn't play badly, so hopefully I can keep this level going," said Nishikori.
For world No. 50 Dolgopolov, it was a third career singles title and his first since Washington in 2012.
"I think you can call it a perfect week. I didn't lose a set here and beat Kei for the first time," said the 28-year-old.
Nishikori was seeking a 12th career crown but he will get another opportunity this week as the top seed at the Rio Open.
In contrast to Nishikori, Frenchman Jo-Wilfried Tsonga had better luck as he recovered to beat David Goffin 4-6, 6-4, 6-1 in the ABN Amro World Tennis Tournament final in Rotterdam to claim his first title since 2015.
Sixth seed Tsonga, 31, fell behind but after levelling the match he swept through the decider against the Belgian.
The 26-year-old Goffin, without a title since 2014, suffered disappointment for the second week running after losing in the final at the Sofia Open to Grigor Dimitrov.
Tsonga once again served well, banging down 10 aces as his power game eventually overwhelmed third-seeded Goffin.
"I'm really happy. These titles come at the right moments. The last couple of months I put in a lot of effort to come back to this level," said Tsonga, who struggled with injuries last season.
"It's a huge reward for me and it gives me new expectations for the rest of the year."
Goffin adopted a brave face, saying: "It was a great week in the end. There was a lot of emotion this week and I won a lot of matches.
"I was a bit tired today. I started the final really well, but in the end Jo played better than me, especially in the third set."
AGENCE FRANCE-PRESSE, REUTERS