The top seed at the ASB Classic women's tennis tournament is pleased with the workout to launch her campaign in Auckland.
Germany's Sabine Lisicki dominated in last evening's 6-4,6-4 win against France's Virginie Razzano to advance to the second round.
But the world number 15 says Razzano, a former top 20 player, demanded her concentration and that was good for her.
Meanwhile fourth seed Flavia pennetta also moved successfully through to the second round.
With her doubles campaign ended on the opening day New Zealand's Marina Erakovic will now concentrate on her singles effort.
This evening the New Zealand number one, ranked 61 in the world will face Germany's Angelique Kerber, ranked at 32.
Sacha Jones was eliminated in the singles yesterday and she now becomes an Australian representative.