By Pritha Sarkar

NEW YORK (Reuters) - It took only 90 seconds and three shanked forehands from Fernando Gonzalez to effectively hand Rafael Nadal a free ticket into the U.S. Open semi-finals on Saturday.

The match which had been delicately poised with Nadal leading 7-6 6-6 and 3-2 in the tiebreak when rain halted proceedings on at 2219 local time on Thursday turned into a damp squib when play finally resumed some 38 hours later.

After spending all day Friday peering out of the players' lounge at a soggy Flushing Meadows, Nadal needed only 34 minutes on resumption to complete a 7-6 7-6 6-0 win.

The swift nature of his romp through the final set came as a huge relief to Nadal as he has been struggling with an abdominal strain and now faces the prospect of playing three days running if he is to reach the final, which has been pushed back to Monday due to the foul weather.

"I have only a little bit problem in the abdominal. That's it," said the third seed, who takes on Argentine sixth seed Juan Martin del Potro in the semi-finals on Sunday.

"When you come back to a situation like today, anything can happen because a tiebreak is a like a lottery and depends on one or two points.

"(Mentally) you can feel good or bad in two points. Luckily I won the first four points today and that proved decisive."

Nadal also earned the added bonus of reclaiming the world number two spot from Andy Murray but his main goal on Saturday had been to conserve as much energy as possible -- especially since Del Potro has already enjoyed a two-day rest after booking his semi-final spot on Thursday.

The Nadal-Gonzalez showdown had been billed as the "battle of the forehands," but it seemed as if the 29-year-old Chilean had left his chief weapon in the locker room on Saturday.

Within a blink of an eye, 11th seed Gonzalez sprayed three forehands to hand Nadal four set points in the tiebreak. The Spaniard needed only one as Gonzalez surrendered meekly with a netted service return.

As Nadal had hoped, the battle had already been lost in Gonzalez's head at the start of the third set. He double faulted on break point to set Nadal on his way to a third set rout.

While Nadal sprinted to his chair, a disgusted Gonzalez sent his racket flying toward the net.

That failed to change his fortunes and even a medical timeout to have tape cut off his ankles offered him little respite.

A male fan in the sparsely filled Arthur Ashe Stadium tried to offer Gonzalez some off-court coaching by shouting "Break a racket."

Gonzalez, who had been warned for his previous burst of anger, wisely decided to turn a deaf ear and instead flooded the arena with 21 errors in the final set alone to seal his own exit -- a forehand into the net ending his ordeal.

Gonzalez, who failed to convert two set points in the opening set on Thursday, struggled to sum up his performance in the match that ended up spanning more than 40 hours.

"I don't have the answer. Maybe I got afraid in the tiebreakers," said the Chilean, whose unforced tally for the three-set match stood at 59.

"I went for it. I miss one. The next point I miss another one, then I miss another one. What else can I do? I try my best," added Gonzalez, who has now lost 13 consecutive sets to the Spaniard.

(Editing by Steve Ginsburg)