NEW YORK – Venus Williams dug herself out of deficits over and over again, until she simply ran out of solutions, exiting the U.S. Open before the third round for the third year in a row.

At 33, two-time champion Williams was the oldest woman in the second round at Flushing Meadows, and while she made things interesting after a poor start to the match and to the final set, she couldn’t sustain her solid play all the way through and lost to 56th-ranked Zheng Jie of China 6-3, 2-6, 7-6 (5) on a wet Wednesday.

The match last 3 hours, 2 minutes — making it the longest between women in the tournament so far — and the third set alone went 1 hour, closing when Williams missed a volley, then a return, on the last two points. She wound up with 44 unforced errors in all, half on forehands.

During her on-court interview, Zheng addressed the partisan crowd that was pulling for Williams, saying: “First, I want to say, ‘Sorry, guys.’

Rain began falling in the early afternoon, jumbling the schedule, and eight women’s singles matches were postponed, including Williams’ younger sister, defending champion Serena, against Galina Voskoboeva. In all, there were more than four hours of delays during the day.

In men’s play that began well into the evening, 2012 champion Andy Murray wasted little time reaching the second round, playing nearly flawlessly during a 6-2, 6-4, 6-3 victory over Michael Llodra.

Murray, who is seeded third, made only five unforced errors, while compiling 34 winners in the 1-hour, 38-minute match. His match was preceded by 2009 U.S. Open champion Juan Martin del Potro’s 6-3, 6-7 (5), 6-4, 7-6 (7) win over Guillermo Garcia-Lopez, which lasted more than four hours.

In the handful of matches that were completed by early evening — men in the first round, women in the second — 2011 French Open champion Li Na, and 2012 Wimbledon runner-up Agnieszka Radwanska won in straight sets, as did 30th-seeded Laura Robson of Britain. No. 17 Kevin Anderson, No. 21 Mikhail Youzhny and 109th-ranked American wild-card entry Tim Smyczek were among the men’s winners.

Venus Williams and Zheng, a former top-15 player who twice reached Grand Slam semifinals, played all of two points at the beginning before their match was interrupted by showers.

When they resumed about two hours later, at 15-all in the opening game, Williams’ play was full of mistakes. In the first set, she only managed to put 46 percent of her first serves in play, and she accumulated 15 unforced errors, 10 more than Zheng. The American, who owns seven Grand Slam singles titles in all, failed to convert any of six break points, while losing serve twice.

And then came the second set, and a significant shift. Suddenly, Williams looked a lot more like the player who won the U.S. Open in 2000 and 2001.

After falling behind by a break in the third set, and being two points away from losing — at 5-3, when Zheng served for the victory, then again in the next game — Williams put up quite a fight to extend the match, drawing raucous support from clapping, yelling and standing fans at Louis Armstrong Stadium. With a drizzle coming down, and play halted on other courts, Williams and Zheng stayed out there and kept going.

Zheng grabbed a 4-1 lead in the tiebreaker, before Williams made one last stand. It was 4-all after Zheng dumped a forehand into the net on a 23-stroke exchange.

Then, at 5-all, Williams put a backhand volley into the net as she lost her footing and sat on the court, wincing. That gave Zheng her first match point, and Williams’ backhand service return was off the mark, ending her stay in the singles draw.

Williams was ranked No. 1 in 2002, but she last was a member of the top 10 when she was No. 9 in March 2011, and she’s currently 60th.

At the 2011 U.S. Open, Williams withdrew before her second-round match, announcing she had been diagnosed with an autoimmune disease that saps energy. She lost in the second round in New York last year.

And her results have faded more, with losses in the first round at two her previous four trips to major tournaments.