Heavy-hitting base liners Garbine Muguruza and Angelique Kerber brushed aside Czech challengers to make a winning start to their WTA Finals campaign on Monday.
Spaniard Muguruza dispatched Lucie Safarova 6-3, 7-6 (7-4) before Germany's Kerber overcame an error-strewn and unwell Petra Kvitova 6-2, 7-6 (7-3) in a battle of the lefties in another White Group encounter.
The 22-year-old Muguruza served confidently, raining down 10 aces, and controlled the baseline exchanges with aggressive strokes on the slower indoor hard court at Singapore National Stadium.