Erik Karlsson's second-period goal stood up as the winner as Sweden dumped Germany 5-2 on Wednesday for its fourth straight victory at the IIHF 2012 world hockey championship.

The Ottawa Senators defenceman found the back of the net on the power play at the 8:14 mark of the middle frame, giving the Tre Kronor a 3-1 edge it would not relinquish the rest of the way in the preliminary matchup at the Ericsson Globe Arena in Stockholm.

Sweden, whose roster also includes captain Daniel Alfredsson and forward Jakob Silfverberg of the Senators, is now 4-0-0 and stands atop Group S (Stockholm). The tournament co-hosts will get their biggest test yet on Friday, when they face unbeaten Russia at the Globe Arena (2:15 p.m., ET). Russia aims for its fourth consecutive victory on Thursday when it squares off against Denmark.

Marcus Kruger and Viktor Stalberg, both of the Chicago Blackhawks, Johan Franzen of the Detroit Red Wings and Niklas Persson also scored for Sweden, which outshot the Germans 45-17.

In games Thursday involving Senators players, Stephane Da Costa and France take on co-host Finland at the Hartwall Arena in Helsinki (1:15 p.m. ET), which Milan Michalek and the Czech Republic face off against Kaspars Daugavins and Latvia in Stockholm (2:15 p.m. ET).

Fans can watch a free stream of all the games on the IIHF's YouTube channel (www.YouTube.com/icehockey).