DRESDEN, Germany (Reuters) - Top-ranked United States beat North Korea 2-0 in their women's World Cup Group C opener on Tuesday with Lauren Cheney and Rachel Buehler on target in the second half.

"You play your first 45 minutes in a World Cup and after those 45 you start knocking the ball around a bit better. We did a good job," U.S. coach Pia Sundhage told reporters.

"It's good to have this result because it is so much easier going forward."

It was the fourth time the two sides had met at a World Cup group stage with the United States, twice world champions, having won two and drawn one of their previous three games.

Three-times Asian champions North Korea battled hard to stifle any American attack outside the box and made the most of their opponents' erratic passing game to venture forward.

American keeper Hope Solo had to come to the rescue twice late in the first half, palming away a Korean shot and intercepting a low cross from Song Jong-sun who was wreaking havoc with Ra Un-sim down the right wing.


The Koreans were lucky not to go a goal down early in the second half when Abby Wambach and 23-year-old forward Cheney each saw their efforts sail just wide as the Olympic champions stepped up a gear.

The Koreans almost struck back two minutes later with Ri Ye-gyong's 25-meter shot rattling the crossbar but apart from this solitary effort it was one-way traffic with the Americans cutting down on errors and pressing their rivals.

Buehler doubled their lead in the 76th minute, sliding and firing in a loose ball after it bounced off the bar.

Substitute Megan Rapinoe pounced on a keeper mistake in the dying seconds to put the ball in the net but her effort was disallowed for a foul on Hong.

Cheney had been a surprise starter instead of Rapinoe and was glad she had been given a chance.

"I worked my butt off and it worked," she told reporters. "I think either of us could have started today."

In the other Group C match of the day, Sweden beat Colombia 1-0.

(Writing by Karolos Grohmann; Editing by Sonia Oxley)