(Photo credit: Geoff Burke-Imagn Images)

MILAN, Italy -- Underdog Italy made podium-contending Sweden work for its 5-2 win in the men's ice hockey group stage on Wednesday and Slovakia stunned defending champions Finland 4-1, as the Olympic tournament delivered thrills on its opening day.

The two Nordic titans were expected to notch routine wins in their respective Group B affairs, with NHL-laden teams in the top-flight professional league's highly anticipated return to the Games after a 12-year absence.

Instead, Slovakia sent Finland searching for answers and the hosts left the packed Santagiulia Arena with pride two days after Italy's women's team booked a Cinderella trip to the knockout stages.

'I don't think the expectations were high from anybody but us,' said Italy's captain Thomas Larkin. 'Our goalies played fantastic tonight and gave us a chance and we were in it 'til the end.'

ITALY PUT UP A FIGHT

Sweden won gold the last time Italy hosted the Games 20 years ago and worked out its early kinks as captain Gabriel Landeskog, defensemen Gustav Forsling and Victor Hedman and forwards William Nylander and Mika Zibanejad each scored.

Swedish goaltender Filip Gustavsson lost his stick as he was coming out to play the puck in the fifth minute and Italy's Luca Frigo leaped on the loose puck and rifled it into the net as the home crowd erupted in utter joy.

Landeskog quieted the cheers when he leveled the game on the power play before Forsling ripped a vicious slapshot past the Italian goalie to grab the lead before the first intermission.

But the Italians made it 2-2 with a bit of trickery early in the second, as Dustin Gazley snuck behind the net and fed the puck to Matt Bradley, who rifled it past the Swedish goalie's glove, again sending the sea of home fans into a frenzy.

Nylander tapped in a rebound late in the second period to take back the lead and New York Rangers center Zibanejad directed the puck into the top-right corner late in the third before Hedman sent one into the empty net to close out the scoring.

Goalie Damian Clara, Italy's homegrown Anaheim Ducks prospect, went off limping midway through the third period, clouding an otherwise dream Olympic debut for the 21-year-old, who turned away 46 shots. Sweden ultimately outshot Italy 60-22.

SLAFKOVSKY SHINES FOR SLOVAKIA

Finland outshot Slovakia 40-25 but was left frustrated by missed chances as goalie Samuel Hlavaj turned away 39 shots in a chippy affair earlier on Wednesday.

Juraj Slafkovsky, Slovakia's Olympic scoring leader four years ago, found the back of the net in the first and third periods, while forward Dalibor Dvorsky scored in the second and center Adam Ruzicka sent one into the empty net late in the Group B clash.

Both teams next play on Friday, with Slovakia taking on host Italy as Finland faces Nordic rival Sweden.

'It wasn't about the one, two, or three players, it was about the 22 guys who battled today,' said Slovakia coach Vladimir Orszagh.

Fans wearing NHL jerseys crowded in with the flag-waving crowd, who cheered wildly as the Montreal Canadiens' 21-year-old winger Slafkovsky got Slovakia on the board with a fine solo effort that ricocheted in off the post in the eighth minute.

A skirmish near the Slovak net ahead of the intermission saw Finland forward Joel Armia in the penalty box for the first two minutes of the second period on a roughing penalty, but the Slovaks could do nothing on the power play.

Once out of the box, Armia fed the puck perfectly to Eeli Tolvanen and the Seattle Kraken winger whipped it past the Slovak goalie to level the contest.

Old NHL grudges spilled onto the Olympic ice as Finnish defenseman Niko Mikkola, who plays for the Stanley Cup champion Florida Panthers, got into it with the Tampa Bay Lightning's Erik Cernak at the end of the second, but both sides regained their composure.

Dvorsky put Slovakia ahead when he flipped the puck over Finnish alternate captain Sebastian Aho, who had fallen onto the ice in front of the net.

Slafkovsky added an insurance goal on a power play and Ruzicka scored into the empty net after Finland pulled its goalie for an extra skater late in the third.

The men's Olympic ice hockey tournament continues on Thursday, beginning with Switzerland vs. France and Czech Republic vs. Canada, both Group A games.

Group C teams play later on Thursday, as the United States face Latvia and Germany plays Denmark.

--Reuters, special to Field Level Media