There was speculation before tonight's concluding contest of the Canada Cup hockey round robin that the unbeaten Soviet Union might take it easy against Team Canada to secure a favorable semifinal matchup against Sweden.

If the Soviets eased up with that in mind, the Canadians might as well stay home Thursday, when the teams meet again in the semifinals. The Soviets, with second-string goalie Alexander Tyzhnykh in the nets, thoroughly embarrassed the home club tonight, 6-3, before a crowd of 12,383.

Two goals 19 seconds apart by Irek Gimaev and Anatoli Semyonov cut a 2-2 tie midway through the second period and thereafter, except for a brief third-period spurt, the Canadians were disorganized.

Besides setting up a rematch of these bitter rivals, the result sent the second-place United States (3-1-1) against No. 3 Sweden (3-2) in the other semifinal Wednesday.

Each team scored twice in a chippy first period, Boston's Rick Middleton and the Islanders' John Tonelli matching a pair by Soviet speedster Vladimir Krutov.

Krutov opened the scoring on a power play at 10:57, after Edmonton's Mark Messier had been sent off for an elbow that bloodied the nose of Vladimir Kovin and much of the ice in the area.

Tyzhnykh came out to knock the puck away from Edmonton's Wayne Gretzky on a short-handed breakaway and, when play moved quickly to the other end, Krutov snapped one over the left shoulder of Calgary goalie Rejean Lemelin from beyond the left-wing circle.

Middleton got that back at 13:03, taking a Gretzky pass in the right-wing circle and shooting through the legs of Tyzhnykh, who unwisely skated far out of his crease.

At 15:05, the entire Canadian bench emptied to congratulate Tonelli. He had netted his first Canada Cup goal while lying on the ice just outside the crease, having been flattened while Tyzhnykh was blocking his initial shot.

Krutov tied it with a short-range lift over Lemelin at 18:30, after Vladimir Zubkov circled the net and passed in front to Sergei Shepelev, who relayed it to Krutov.

Although Swedish referee Dag Olsson called only three penalties, two to Canada, he overlooked a lot of other possibilities as the Canadians played aggressively and the Soviets used their sticks to chop down the home side.

The Soviets took a 4-2 lead in the second period as Irek Gimaev and Anatoli Semyonov beat Lemelin 19 seconds apart.

After the two Soviet goals, the Canadians began running around out of position and had difficulty setting up any scoring plays. On the period, they were outshot, 6-3.

A roughing penalty to the Islanders' Brent Sutter with 22 seconds left in the period aroused the ire of the crowd, since Sutter had been held for some time by Semyonov before he punched him.

The score became 5-2 at 2:33 of the third period. Mikhail Varnakov skated down the middle, took Sergei Shepelev's pass and beat Lemelin on the stick side with the Canadian defense caught completely out of position.

The five goals equaled the Soviets' total against Lemelin in a 5-4 exhibition victory at Montreal Aug. 29. Lemelin was cut the next day, but recalled last week when Edmonton's Grant Fuhr was hurt.

Canada rallied in the last 10 minutes. Quebec's Michel Goulet trimmed the margin to 5-3 at 10:52, converting Gretzky's pass out of the right-wing corner.

Thus encouraged, the Canadians swarmed around the Soviet net. Tyzhnykh made a good stop on Bourque, then Islander Mike Bossy shot the rebound wide. With Tyzhnykh out of the net, Canada got off three shots that either struck other defenders or went wide.

Sergei Makarov concluded the scoring into an empty net with 19 seconds remaining.