Vesalainen's long shot with 11 minutes left deflected in off defender Deniss Smirnovs, and the Finns celebrated with relief.

"I just shot the puck to the net and I don’t know what happened," said Vesalainen. "Pretty lucky goal."

The underdog Latvians allowed a tournament-worst 29 goals in four group stage games, but hung tough here to keep this one close. Finland outshot Latvia 45-24, and Latvian starting goalie Marek Mitens was tremendous.

"It’s not easy when you have just one goal after 40 shots or something like that," said Finnish captain Olli Juolevi. "Those guys got more confidence and their goalie was super-hot after that. But the good thing is we finished the job."

Like Latvia, the snake-bitten Finns scored six goals in group play, also a tournament low. The Finns won gold at last year’s tournament in Helsinki, and originally expected to compete in the quarter-finals. However, they opened with three regulation losses to the Czechs, Danes, and Swedes, and were doomed to the relegation round after Switzerland’s 5-4 shootout win over Denmark.

In a surprising move, coach Jukka Rautakorpi was fired before Finland's game against Switzerland and replaced by Jussi Ahokas, who coached Finland to U18 gold in April.

Game Two goes Tuesday at the Bell Centre. Game Three is Thursday (if necessary).

Villi Saarijarvi also scored for Finland. Maksims Ponomarenko replied for Latvia.

Asked about coach Erik Miluns's message to the team, Mitens said: "They were champions last year but they’re not this year. So we’ve got to play on the same level."

The Latvians came out aggressively, but the Finns soon picked up the tempo. Near the five-minute mark, Henrik Borgstrom and Juuso Valimaki hit posts back-to-back. At 7:43, Saarijarvi stepped in from the point on the power play and wired a high wrister past Mitens for a 1-0 lead.

Midway through the first period, Mitens made a nice in-close save off Julius Nattinen off the rush. He also foiled Janne Kuokkanen, who split the Latvian defence and tried to sift a backhand through the five-hole. Finland outshot Latvia 21-11 through 20 minutes and could easily have led by more, with two late power plays.

"We knew they were going to play pretty defensively," said Juolevi. "They were trapping a lot in the neutral zone."

Latvia tied it up at 4:37 of the second period. Ponomarenko's shot from the blue line whizzed past Finnish goalie Veini Vehvilainen's glove. It was the first goal of the tournament for the 19-year-old defenceman, who plays for Lorenskog IK in Norway.

Next, it was Finland's turn to parade to the penalty box, but Latvia couldn't find the go-ahead goal, even with a long 4-on-3 man advantage.

In the third period, Nattinen and Joona Luoto misfired on a great odd-man rush chance near the six-minute mark. Shortly after Vesalainen's go-ahead goal, Mitens grabbed an Eeli Tolvanen shot that nearly trickled over the goal line with 8:13 left.

The Latvians got one final gasp with 12 seconds left when Aapeli Rasanen was sent off for cross-checking Eduards Tralmaks in the Finnish zone. But even with Mitens pulled for the extra attacker, they couldn't cash in.

Mitens stayed optimistic post-game: "We’re feeling confident. It’s only one game. It doesn’t matter. We’ve still got two games left. We’re gonna beat them in two games. That’s it."

Finland is the first defending World Junior champion in history that has had to play relegation games. The Finns’ previous worst tournament finish was seventh (2000, 2009, 2013, 2015).

Newly promoted Latvia is playing in its sixth elite World Juniors since 2006. The Latvians managed to avoid relegation twice before, in 2009 and 2012.

"That’s our mission to stay in the highest group," said Latvia's Tomass Zeile. "If we would knock Finland out, that would be really big, to beat last year’s champions. For next year, to keep progressing for the 98’s and 99’s, to keep investing in hockey in the country, that’s huge."