(Photo credit: Susan Mullane-Imagn Images) Tallon Griekspoor of the Netherlands used his strong serve to upset No. 2 seed Alexander Bublik of Kazakhstan 6-3, 7-6 (4) in the Round of 16 at the Dubai Duty Free Tennis Championships on Wednesday. Griekspoor fired off 14 aces without a double fault and won 35 of 40 first-service points (87.5%). He also saved three break points and had just 10 unforced errors to