Olympics-Ice hockey -Donato at the double as U.S. men advance to last eight

* Donato tied for Olympic goal scoring lead with four

* U.S. advances to play Czechs on Wednesday

* Americans' college players continue to shine (Adds player and coach quotes, details)

GANGNEUNG, South Korea, Feb 20 (Reuters) - Ryan Donato scored twice to help the United States ease to a 5-1 win over Slovakia on Tuesday and book a spot in the men's Olympic ice hockey quarter-finals.

The Americans' scoring burst topped their entire output so far in Pyeongchang and again came on the strength, energy and speed of their small corps of college players.

Linemate Troy Terry from the University of Denver had three assists but it was the Harvard standout Donato's second two-goal performance that provided the spark and also moved him into a tie as the tournament's top goalscorer with four.

Donato also scored twice in the Americans' previous 2-1 win over the Slovaks in group play.

"It's do-or-die obviously. We came in with the intention of being confident, not just being worried about going home. If we had played on our heels and played worried, it would have affected our game," Donato said.

"I think we just played confident, and the chemistry is continuing to grow, and it's finally meshing."

After a scoreless first period, the U.S. raced clear with three goals in the second as Donato set the ball rolling when he snapped in a loose puck past goaltender Jan Laco after Terry's errant shot on a breakaway had come back off the boards.

Less than a minute later, Donato took a check to the head from Michal Cajkovsky, who was given a five-minute major penalty and a match suspension, after Ladislav Nagy had interfered with U.S. goaltender Ryan Zapolski to draw a two-minute penalty.

On the ensuing two-man advantage, U.S. defenseman James Wisniewski scored from the left circle with a low slap shot, his trademark talent and the main reason why coach Tony Granato had slotted the ex-NHL player onto the U.S. team.

"When the game was on the line, that five-on-three was huge," Granato said.

"And we got him (Wisniewski) there for one reason, to shoot the puck on the powerplay. And you couldn't have found a better time to get his first one. That was a big one."

The U.S. made it 3-0 when Mark Arcobello, crossing into the low slot, one-timed a feed from Terry from behind the Slovak net. Terry assisted on all three U.S. second period goals.

The Slovaks got on the scoreboard later in the period with a power-play goal when Jordan Greenway was in the penalty box for slashing, Peter Ceresnak's slap shot from the point deflected by a U.S. stick and past a stranded Zapolski.

Slovakia's comeback attempt ended there, however, as Garrett Roe got his first Olympic goal midway through the third period to reestablish a three-goal cushion for the Americans.

Donato got his second goal of the game, and now leads all U.S. scorers, late in the third period on a power-play, firing a wrist shot that beat Laco just inside the near post to complete the scoring.

With his performance on Tuesday, Donato tied his father Ted in Olympic goal-scoring.

Ted Donato, a former Boston Bruin player and now the coach at Harvard, had four goals and three assists in 1992 at the Games in Albertville, France and had just arrived in Pyeongchang with Tuesday's game being the first he had seen in person.

"I saw some videos of him in between periods, celebrating. I've never seen him smile like that before," Donato said. "It was good to see that."

The victory set up a quarter-final showdown against the Czech Republic, who were undefeated in pool play, on Wednesday, while Slovakia were eliminated from the tournament. (Reporting By Dan Burns; Editing by John O'Brien and Sudipto Ganguly)