That was an almost flawless performance," Querrey said."If he can sustain that level for five more matches, there's no reason to think he doesn't have a good shot at the title."While Djokovic's form has been impressive in his opening victories over Yibing Wu and two-time major finalist Tsitsipas, the Serb has spent a lot of his time between points limbering up his 39-year-old body.And while his Greek opponent was taking his customary break between the second and third sets, Djokovic was feeling relaxed enough to have some fun with a ball kid.He was trying to cut off a bit of excess material from his shoulder when he asked for some assistance.As she looked to make the cut, Djokovic flinched as if she had caught his skin, making her jump.He quickly apologised as the crowd chuckled and she put her hand at her heart, and he made sure to apologise immediately after the match too while she laughed courtside."This kind of thing surfaces when you're two sets to love up," he said."Stefanos went to change so I had some spare time."I'm sorry if I scared her It made me a bit more relaxed."Djokovic next plays French 25th seed Arthur Rinderknech.Earlier, top seed Jannik Sinner took on Portugal's Nuno Borges and after the hazards the Italian faced in his five-set win over Serbia's Miomir Kecmanović in his opener, the 24-year-old kept it straight down the middle to reach round three.World number 48 Borges had a set point in the second set, but Sinner was relatively untroubled as he raised his game at the pivotal moments for a 7-6(7/4), 7-6(7/2), 6-4 victory."Second match on grass, I was not looking for perfection," Sinner said."I tried to improve