Rafael Nadal hit back from a set down to beat fellow Spaniard Fernando Verdasco in Hamburg.
Thomaz Bellucci enjoyed a straight-sets win over Kimmer Coppejans to reach round two of the Swiss Open in Gstaad.
Fourth seed Kurumi Nara fell at the first hurdle of the Baku Cup following a straight-sets defeat to Olga Savchuk.
The Lawn Tennis Association says it is making positive progress as it seeks a new performance director.
Gilles Muller moved into the second round of the BB&T Atlanta Open after a straight-sets victory over Donald Young.
Top seed Anastasia Pavlyuchenkova battled to a comeback victory over Elizaveta Kulichkova in the Baku Cup.
Jerzy Janowicz reached the second round of the bet-at-home Open with a 6-4 6-3 victory over Taro Daniel.
Qualifier Horacio Zeballos has set up a showdown with top seed David Goffin at the Swiss Open in Gstaad.
Top seed Tatjana Maria has breezed into the second round of the Brazil Tennis Cup in Florianopolis.
A look at how the latest sports news has affected the major betting markets, including the Sussex Stakes.