Sixth seed Querrey beat 11th seed Jarkko Nieminen 4-6, 7-6 (7/4), 7-6 (12/10) a day after the 40th-ranked Finn had advanced when American Mardy Fish could not continue due to heat stroke.
He has missed months of action at a time over the past two seasons. On Tuesday, Fish stopped playing in the third set of his match against Jarkko Nieminen at a hard-court tournament in Winston-Salem, N.C., because of heat stroke.
Fish will take on Jarkko Nieminen of Finland in the second round of men's final tuneup event before the U.S. Open
Davydenko is the highest seed to fall so far in Montpellier. Ninth seed Paul-Henri Mathieu was earlier knocked out by Ukraine's Sergiy Stakhovsky.
Young Australian Bernard Tomic took a major step towards winning his first career ATP Tour title by downing defending champion Jarkko Nieminen at the Sydney International on Thursday.
Jarkko Nieminen of Finland and Russia's Mikhail Youzhny advanced to the second round of the Stockholm Open on Monday with straight-set wins.
Gilles Simon upset top-seeded Janko Tipsarevic 6-4, 6-4 on Saturday to set up an all-French final against Richard Gasquet at the Thailand Open.
John Isner overcame a rare tiebreaker loss to advance at the U.S. Open with a second straight four-set win.
Britain's Andy Murray progressed to the third round of the Olympics without any drama as the world number four defeated Finland's Jarkko Nieminen 6-2, 6-4 on Tuesday.
A fully fit again Andy Murray reached the last 16 of the French Open on Saturday with a 6-3, 6-4, 6-4 win over Santiago Giraldo of Colombia.
Andy Murray overcame crippling back pain to battle his way past Jarkko Nieminen into the third round of the French Open on Thursday.
Rafael Nadal emerged a 6-4, 6-3 winner over Jarkko Nieminen with no obvious discomfort to his troublesome left knee as the Spaniard began his quest for a record eighth title at the Monte Carlo Masters on Wednesday.
Finland's Jarkko Nieminen beat Julien Benneteau 6-2, 7-5 in the rain-delayed Sydney International final Sunday, sealing a remarkable tournament win after he came through qualifying.
Gael Monfils won his first title in a year on Sunday when he defeated Jarkko Nieminen 7-5, 3-6, 6-2 to claim the Stockholm Open crown.
Top-seeded Gael Monfils beat No. 6 Milos Raonic 6-7 (6), 6-4, 6-3 on Saturday to set up a Stockholm final against Jarkko Nieminen.
Jarkko Nieminen defeated James Blake 7-6 (5), 5-7, 6-2 Saturday to reach the Stockholm Open final for the third time in his career.
Gael Monfils of France was the only seeded player to progress in a day of upsets in the second round of the Stockholm Open on Thursday.
France's Gael Monfils, returning to tennis after an injury layoff, reached the semi-finals of the ATP Thailand Open on Friday with a 7-5, 7-6 (7/4) win over Jarkko Nieminen.