Andre Agassi's season debut ended with a 6-4, 6-2 quarter-final loss to unseeded Guillermo Garcia-Lopez at the Delray Beach International Tennis Championships on Friday.
Top seed Agassi never found his rhythm against the Spaniard, who needed just 74 minutes to dispose of the eight-time grand slam winner.
"He was out-hitting me," said Agassi on the ATP Web site. "I wasn't reacting well to the ball.
"I haven't gotten my game together. It will take matches and time to work that out.
"I can't realistically come here and expect to feel that comfortable on the court."
Agassi put up a determined fight in the first set but the 35 year old ran out of steam in the second at 2-2, as Lopez swept the next four games to take the match.
Lopez will next meet third seed Xavier Malisse of Belgium who advanced with a 6-7, 6-2, 6-3 win over Germany's Florian Mayer.
Eighth seed Vince Spadea of the United States swept South Korea's Lee Hyung-taik 6-3, 6-3, while fourth seed Tommy Haas of Germany was upset by Luxembourg's Gilles Muller 6-3, 6-2.
