* Rain plays havoc with schedule
* Patient Murray in no mood to hang around
* Blake sent into retirement (Updates with Murray winning)
NEW YORK, Aug 28 (Reuters) - He waited a lot longer than he expected but Andy Murray finally began his U.S. Open defence on Wednesday with an emphatic straight-sets victory that lit up an otherwise gloomy day at Flushing Meadows.
A quirky schedule combined with persistent rain left Murray waiting until almost 10PM ET (0200 GMT) on the third night before he finally started his first-round match against Frenchman Michael Llodra.
With his patience beginning to wear thin, the Scotsman was in a hurry to make up for lost time in his first match back at Arthur Ashe Stadium since he won his first grand slam title 12 months ago.
He whipped Llodra 6-2 6-4 6-3 in just over 90 minutes with a brilliant display of shotmaking that left the New York crowd wanting more on a day when dozens of matches were postponed because of foul weather.
"It was more kind of going back onto that court again... obviously I have great memories here from last year," Murray said.
"I didn't necessarily feel like I had much time to enjoy last year because I was so relieved. I was also a little bit in disbelief, as well.
"To actually be out there and play a night match in front of a big crowd was really nice. I performed well. It was good."
Of the remaining matches that were completed, Venus Williams was the biggest casualty, sent packing following a 6-3 2-6 7-6(5) loss to China's Zheng Jie after the pair had slugged it out for more than three hours.
Once the undisputed Queen of Flushing, the 33-year-old American's best days now seem behind her after she crashed to her third successive second-round defeat at the U.S. National Tennis Center.
She did at least provide a memorable reminder of her fighting qualities as she clawed her way back and pushed the match into a deciding tiebreak only to falter at the death with successive errors.
"I just dug myself into so many holes the whole match." she said. "I just fought as hard as I could to get out of them, but sometimes it wasn't enough."
Two other former champions, Argentina's Juan Martin Del Potro and Australia's Lleyton Hewitt, fared better, surviving tough battles to set up a second-round clash.
Del Potro, the winner in 2009, beat Guillermo Garcia-Lopez of Spain 6-3 6-7(5) 6-4 7-6(7) while Hewitt, who won in 2001, wore down American qualifier Brian Baker 6-3 4-6 6-3 6-4.
In the women's draw, Poland's Agnieszka Radwanska, the third seed, easily defeated Maria-Teresa Torro-Flor of Spain 6-0 7-5 while China's Li Na just beat the first rain falls to dispose of Sweden's Sofia Arvidsson 6-2 6-2.
"I was a little bit happy because at least I'm done for my job today," said Li.
Around four hours of play was lost on the day because of showers that sent players and spectators scampering for cover then continued to drizzle.
Another downpour in the afternoon prompted officials to postpone 28 matches until Thursday, including the second round match featuring Serena Williams, in order to complete the men's first round, which is played over three days at the U.S. Open.
The first round did not finish until after midnight when Ivo Karlovic sent James Blake into retirement with a 6-7(2) 3-6 6-4 7-6(2) 7-6(2) win on Louis Armstrong Stadium.
Blake, a former world number four, announced on Monday he was quitting after his involvement in the tournament ended.
New York's fickle weather has been a major talking point at the last grand slam of the season for years with each of the last five men's finals spilling into a third week because of rain delays.
The problem has been exacerbated because of the tournament's controversial scheduling.
Apart from playing the men's first round over three days, the U.S. Open was previously the only grand slam where both singles semi-finals and finals were played on successive days, leaving no room for catch-up if rain falls on the last weekend.
Tournament organisers changed the schedule this year to provide a day off between the semi-finals and final, but remain powerless to combat Mother Nature because they have no roof unlike the other grand slam events.
For years, U.S. Tennis Association officials balked at the idea of building one because of the cost of covering Arthur Ashe Stadium, the largest tennis stadium in the world.
But they have finally relented, announcing two weeks ago they would commence a massive renovation program, which would include a retractable roof, but not until 2016 at the earliest. (Editing by Greg Stutchbury)