Tim Belcher, a fast-balling pitcher who was the No. 1 major league draft choice last June, had a rough debut today at the Pan American Games. The Minnesota Twins' choice was knocked out early in the game but the U.S team defeated Canada anyway, 10-5, after a 20-minute power failure in the seventh inning.

Belcher was chased after only 2 2/3 innings and the score tied at 4. He was tagged for five hits and walked two in his short stint.

Things went much better for flyweight Steve McCrory of Detroit, Mich., who started the U.S. boxing team's participation in the games by scoring a controversial decision over Panama's Jorge Garcia.

In other action, weight lifter Daniel Nunez of Cuba set a world record in the snatch for the 132-pound category. He broke his own record of 302 1/2 pounds that he set in 1982 by one pound.

In men's basketball, Michael Jordan, North Carolina's 6-foot-5 all-American, scored 27 points to rally the United States team to a 72-69 victory over Brazil, after trailing, 55-45, with less than 11 minutes to play.

Jordan scored 17 points in the last 10 minutes. Sam Perkins, Jordan's college teammate, contributed 15 points.

Deena Wigger, 16, helped the U.S. win four more gold medals in the shooting competition. Wigger, daughter of two-time Olympic champion Lones Wigger of Fort Benning, Ga., won the women's English Match event.

The U.S. women's softball team came back from a Monday loss to Puerto Rico by beating Venezuela, 16-0. The U.S. water polo team beat Canada, 17-5, and Greg Holmes of Danville, Calif., defeated Marco Morales, Chile, 6-1, 6-1, in the second round of tennis competition.

The U.S. added nine gold medals, including six more by its shooting team and three in judo by Chris Penick, Robin Chapman and Brett Barron, to overtake Cuba for the lead, 13-12. The U.S. maintained the overall medals lead with 24.

If the United States wins the gold medal in baseball at the Pan American Games, the U.S. Olympic Committee should vote a special award to Calvin Griffith, the frugal owner of the Minnesota Twins.

Representing the U.S. here are the Twins' first three picks in the June draft, pitchers Tim Belcher and Billy Swift and catcher John Marzano. All talked contract with the Twins and none came close to being satisfied.

Belcher had made it clear that he was anxious, at age 21, to get started on his pro career.

About two dozen players who tried out for the Pan Am team eventually signed pro contracts, according to Coach Bob Bennett of Fresno State. Belcher was not among them.

"It's to my advantage to sign now, when I've got that top pick going for me, and I won't get as much if I wait till the next draft in January," Belcher said.

"But I've been discouraged all summer, because it looks like negotiations with me are not a hot item with the Twins.

"One of the things that discouraged me was the fact that we had talked about all this before the draft. It sounded like a great system. I let them know what I wanted--in the $130,000 to $160,000 range--before the draft and I figured if they didn't want to pay it, they'd draft someone closer to their figure.

"Their first offer was $80,000 and their last was $110,000--100,000 bonus, $7,000 incentives and $3,000 for my last year of school. At times I feel guilty for saying no, because I really want to get into pro ball, but what I'm asking isn't outrageous. It's less than the normal No. 1 draft. Heck, the Mets have already signed the No. 4 pick for in excess of $150,000."

In Minneapolis, Griffith said that this was the first time Minnesota has had the nation's top choice, "And I hope we never have it again."

He said Belcher has not proved himself. "He had a mediocre year in college, 5-4 (at Mount Vernon Nazarene in Ohio), and got beat two games in Tokyo pitching for the U.S. team. Yeah, we'd let him go."

Although Belcher, 6-feet-3 and 215 pounds, pitched for a small college, he had no trouble attracting the attention of major-league scouts.

Belcher has the greatest potential on the U.S. pitching staff, although he is in good company, as John Hoover showed Monday in a five-hit shutout while the U.S. breezed past the Dominican Republic, 8-0.

In the recent Intercontinental Cup in Belgium, Belcher struck out 15 in a 5-1 win over Korea and went 8 1/3 innings to beat the Netherlands, 6-3.

Belcher has pitched only one inning of relief in three meetings against Cuba, all of which the U.S. lost. He is hopeful Bennett will let him start if the teams clash, as expected, during the six-team round-robin final here. They are in different preliminary groups.

"The staff figures the Cubans are a good fast ball-hitting team and I agree," Belcher said. "But I'd like a shot at them. I don't care if they're the best fast ball-hitting team in the world."

"It's a great opportunity to see the world and represent my country," said Belcher about playing on the Pan Am team. He has also played in Japan, Belgium, The Netherlands and Aruba.

"I don't feel like I'm hurting myself. The Cubans are comparable at least to double-A ball and the rest are A ball, so I'm getting good experience. Coming from a small college, this is sort of easing me in."