Andy Murray's US Open preparations got off to an ignominious start as he crashed out of the Citi Open in Washington at the first hurdle.
The Scot went down 6-4 3-6 7-6 (7/4) to Russian Teymuraz Gabashvili, the world number 53, in their second-round clash in two hours and 42 minutes.
Murray served for the match at 5-4 in the decider, but was broken and then went on to lose the tie-break and with it his first match since helping Great Britain to a Davis Cup win over France.
The world number three said on the ATP Tour website: "I normally back myself to return a little bit better than I did. I think in the tie-break I don't think I put one return in the court when he was serving. I feel like I didn't do a good enough job of putting enough first serve points in the court.
"It's obviously a disappointing match to lose, but it wasn't like I was blown off the court in a match that I had no chance of winning.
"I feel like I put myself in a position to win the match. It was the first hard-court match for four-and-a-half months with only four or five days of preparation, so I was happy with how I moved and did certain things on court.
"But there are some things for me to improve and hopefully with a few more days and having that match under my belt I'll be able to make some improvements for the next few weeks."
Murray was just one of a number of seeds to tumble, with South Africa's Kevin Anderson, Serbia's Viktor Troicki, Croatia's Ivo Karlovic, Australia's Bernard Tomic and Pablo Cuevas from Uruguay also all going out.
Fifth seed Anderson went down 2-6 6-3 6-4 to Germany's Alexander Zverev, ninth seed Troicki lost 6-3 6-4 to Australia's Sam Groth and 10th seed Karlovic was beaten 6-4 7-6 (7/2) by Ukraine's Alexandr Dolgopolov,
Tomic, the 11th seed, fell to a 6-7 (7/9) 6-4 6-2 defeat to American Steve Johnson and 14th seed Cuevas slumped to a 6-3 6-3 loss to Lithuania's Ricardas Berankis.
Fourth seed Richard Gasquet had to come from a set down to see off Luxembourg's Gilles Muller, the French Wimbledon semi-finalist triumphing 5-7 6-4 6-4 thanks to a single break in each of the last two sets.
Grigor Dimitrov, the sixth-seeded Bulgaria, was a 7-6 (7/1) 6-4 winner over Argentinian qualifier Guido Pella.
Spanish seventh seed Feliciano Lopez clinched a 4-6 7-5 6-3 win over veteran Australia Lleyton Hewitt, while John Isner, the eighth seed from the United States, beat Dominican Victor Estrella Burgos 6-3 7-6 (7/5).
Leonardo Mayer, the 16th seed from Argentina, came through a marathon meeting with Slovenia's Blaz Rola 7-6 (7/2) 6-7 (3/7) 6-4.