Monaco, No. 10 in the world, was looking for a good showing in Valencia to support his attempt to gain an invitation to the ATP World Tour Finals. However, Hewitt's 6-3, 6-4 win marked the third consecutive match loss for Monaco.
Hewitt finished with five breaks and won more than half (30-28) of the points when Monaco served. Hewitt even won most of the points when Monaco, last year's runner-up in Valencia, was good on his first serve.
No. 5-seeded John Isner faced just one break point after the first set of a 6-3, 6-7 (4-7), 7-5 win over Fabio Fognini. Isner won more than three-quarters of the points on serve.
Qualifier Ivan Dodig got past Philipp Kohlschreiber 6-2, 7-6 (8-6) in a match that took nearly 2 hours. Dodig pounded out 11 aces and saved all six of Kohlschreiber's break chances.
Other first-round results Monday saw Fernando Verdasco defeat Tommy Robredo 6-3, 6-4; David Goffin beat Pablo Andujar 6-2, 6-2; and Albert Ramos topped Rajeev Ram 6-3, 6-3
Rosie O'Donnell unveils nearly 50-pound weight loss
Justin Bieber crashes Drake Bell's album release party