Serving for the match at 5-4 in the fourth set, an increasingly dispirited Fish lost seven consecutive points -- a critical shift in momentum that ultimately proved fatal. The match ran for 3 hours, 11 minutes, far longer than Fish has been able to practice or play in recent years.
Fish (left hamstring) cramped repeatedly in the final games, to the extent it affected his shots. He could barely bend over to pick up his rackets and stow them in his bag.
Suffering from heart and anxiety disorders for the past three years, Fish announced that this US Open would be his last tournament. The 33-year-old said he was seeking closure, hoping to write a new narrative at his favorite event after withdrawing from a fourth-round match against Roger Federer in 2012.
This was career closure, of course, but hardly the triumphant story arc in front of a jam-packed Louis Armstrong Stadium that Fish hoped for.
The one thing he feared, Fish said after his first-round match, was the broiling weather conditions. After losing the first set to Marco Cecchinato on Monday, he buckled down and won the last three. For what it's worth, it was physical issues that doomed Fish, not mental ones.
Fish actually outplayed Lopez for most of the match. He forced 18 break points, but could only convert six. Lopez, who on a number of occasions bailed himself with an ace, was a more efficient 5-for-7.
Throughout the match, Fish appeared to be holding back, as if trying to conserve energy. Lopez had the upper hand in terms of power, averaging 125 mph on his first serves, 16 mph faster than Fish averaged.
At the end, Fish did not consent to an on-court interview. Instead, he walked slowly to the middle of the court and did a 360-degree turn, waving to the standing patrons.
This was only the sixth match of the year for No. 581-ranked Fish, but he leaves a lively legacy: An overall record of 302-219 (.580), six titles and three Grand Slam quarterfinals, in Australia (2007), here at the US Open (2008) and Wimbledon (2011).