Johanna Konta beat Alison Riske in straight sets to move into the round of 32 at the Mutua Madrid Open.
The 27-year-old, playing a day after losing the final of the Morocco Open, showed no signs of tiredness as she took the first set 6-4 before finding her stride to take the second 6-1.
World number 47 Konta will face the tournament's third seed, Simona Halep, in the next round.
Halep beat tournament qualifier Margarita Gasparyan 6-0 6-4 to set up the round of 32 match with Konta.
Top seed Naomi Osaka booked her place with a 6-2 7-6 straight-sets victory over the Czech Republic's Dominika Cibulkova.
Fourth seed Angelique Kerber and last year's winner Petra Kvitova also won in straight sets.
Kvitova beat the United States' Sofia Kenin 6-1 6-4 while Kerber won 6-3 6-2 against Lesia Tsurenko.
