The two sides came into this with one win and one loss each from their opening Group B clashes - both had earned a big win over Denmark, but while Sweden were beaten by favourites Canada, Czech Republic had fallen to a surprise overtime loss to Slovenia.
Hurting from that defeat, the Czechs played the first 13 minutes with all the hallmarks of a side with a point to prove, scoring three unanswered goals to stun the Swedes. The first came after three minutes, when Filip Hronek's shot from the blue line was tipped in by Matej Blumel.
Tempers were starting to flare just five minutes later as both sides had a player penalised for roughing, but when Ivar Stenberg was also sent to the box three minutes later, the Czechs took the chance to double their lead on the powerplay through Dominik Kubalik's one-timer from distance.
And it was 3-0 just over 30 seconds later, when Daniel Vozenilek came away with the puck after a real scrap behind the Swedish net, and laid it back for Jakub Flek to score from close range despite the best efforts of goaltender Magnus Hellberg.
After the goal, further fights broke out, and following a lengthy review, the Czechs lost Jan Scotka, who was ejected for cross-checking.
That decision completely swung the momentum, and the five-minute powerplay gave Sweden a route back into the match. Midway through the advantage, a neat reverse pass from Emil Heineman found Joel Persson in space, and he had time to set himself before firing through the crowd.
That got Tre Kronor on the board, and with time winding down on the powerplay, they made it a one-goal game again, with Heineman and Persson again involved, moving the puck quickly before setting up Simon Holstrom for a powerful strike.
Czech Republic were happy to get back to full strength and they made a bright start to the second period and added their fourth in the fourth minute, as Jiri Cernoch attacked through the centre and played a one-two with Ondrej Beranek before taking a shot which had just enough on it to beat Hellberg - a video review was needed to confirm the puck had crossed the goal line.
Yet again, Czech indiscipline was to allow Sweden back into the game - less than a minute after scoring, Hronek was guilty of boarding, and after patient build-up, Oliver Ekman-Larsson took matters into his own hands, rifling the puck into the roof of the net to make it 4-3.
After the midpoint of the match, Stenburg was guilty of hooking, but the powerplay was cancelled out seconds later following a trip from Roman Cervanka. Neither side profited from the 4-on-4, and Czech Republic held on to take their narrow lead into the final 20 minutes.
Sam Hallam's side wasted the chance to level early in the third period after hooking by David Tomasek, but this time the Czech defence survived the powerplay. That set the tone for a final period in which the Czech back line were on top, as Sweden had 11 shots on goal to their opponents' one, but couldn't find a way through.
The Swedes pulled Hellberg in the final minutes in favour of an extra attacker, but the Czechs dug in and took the 4-3 victory. Radim Rulik's side move onto seven points, behind only Canada, while there's work to do for Sweden, who have three points from their three matches and sit fifth.
Sweden are back in action against Slovenia on Wednesday 20th, as Czech Republic take on Italy on the same day.
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