Rafael Nadal battled past German Tommy Haas 7-6, 6-3 to reach the Cincinnati Masters quarter-finals.
Spain's Nicolas Almagro won his second title in successive weeks on Sunday when he beat Juan Ignacio Chela 6-3, 3-6, 6-4 in the final of the Buenos Aires Open.
The Briton he lost in the third round to slow court specialist Mariano Zabaleta.
The Indian ace and his Czech partner Tomas Cibulec crashed out of the men's doubles at the Australian Open in the first round.
They posted comfortable semi-final victories over Jean Rene Lisnard of France and Juan Ignacio Chela of Argentina respectively in the Tata Open tennis tournament.
Rafael Nadal survived an early scare at the Barcelona Open on Friday to beat Argentine Juan Ignacio Chela 6-4, 6-2 for a place in the semi-finals.
Argentina came back from the brink to snatch a thrilling 2-1 victory over the Czech Republic in Saturday's final and capture the World Team Cup for the third time.
The Argentine No 1 overpowered Russia's Marat Safin in the second singles after Nikolay Davydenko beat Juan Ignacio Chela.
Andre Agassi reached his first final of the year at the Los Angeles Open with an easy 6-4, 6-2 win over Argentine Juan Ignacio Chela