The hard-serving Querrey fired 15 aces, but was down in the pivotal ninth game of the third set Thursday. Four serves and two aces later, he took a 5-4 lead and then broke Davydenko at love to close out the match.
Davydenko needed a doctor to look at his right wrist midway through the match. He said it became sore from the force of Querrey's serves hitting his racket.
Elena Vesnina earned a spot in the women's semifinals earlier, defeating Anna Chakvetadze in straight sets, 6-1, 7-5.
Bolton close on EmanaTop-seeded Davydenko advances at Pilot Pen
