US Open: Phenomenal Tsvetana Pironkova is in form

Unranked Bulgarian Tsvetana Pironkova extended her US Open giant-killing run on Saturday, scoring a second consecutive upset with a straight-sets defeat of 18th seed Donna Vekic.

Pironkova, who is playing her first tournament in three years, polished off Croatia's Vekic 6-4, 6-1 in just over an hour. Pironkova, 32, who had...