On paper, it was a battle between the first and 16th-placed teams of the Regular Season but the First Game of the Round of 16 was an absolute mind-blower as the Rapperswil-Jona Lakers toppled German giants Adler Mannheim.

Four goals were enough to secure a win in regulation for the Swiss team. Forward Jordan Schroeder was instrumental with two goals, while netminder Melvin Nyffeler made 19 saves and allowed a single goal. The victory gives Rapperswil a three-goal aggregate lead heading into their Return Game next week.

Rapperswil had their first chance to strike at home after Mannheim's top scorer David Wolf was called for interference, and just over a minute into the powerplay, the hosts converted. American forward Schroeder collected a tip off a shot wristed in to beat Mannheim's netminder Felix Brückmann at 7:44. 

The 1-1 equaliser would come less than four minutes later, off a pass from blueliner Paul Mayer to Linden Vey who was stationed on the goal line and had no issues jamming the puck past Nyffeler. 

A roughing call on Lakers defenceman Fabian Maier gave Mannheim their first man-advantage of the evening but they had no luck converting. 

With less than three minutes remaining in the first period, Rapperswil's Martin Frk got the crowd going after he dished the perfect pass to teammate Gian-Marco Wetter. It was Swiss precision from Top Scorer Wetter, who slid the puck past Brückmann to put his side 2-1 up leading into the period intermission.

Minutes into the second period Rapperswil would be handed another chance to extend their lead with powerplay number two, but couldn't find the back of the net despite several excellent chances. 

Rapperswil were running hot, while their German rivals struggled to find their flow, although Wolf had a great chance on the doorstep of Nyffeler. 

With a little under two minutes left in the period and a powerplay incoming, Mannheim pulled their goalie for a sixth man on the ice. Despite no luck coming before the sound of the buzzer, they'd start the third period with fresh legs and the tail-end of a powerplay.

The Swiss side continued their dominance in the third period, netting goal number three through Schroeder who picked up his second goal of the night. A backhand shot rifled in by Nicklas Jensen was a near miss on Brückman who momentarily lost sight of the loose puck, while Victor Rask followed that up with a near miss of his own. 

A slashing call on Dominic Lammer gave Mannheim a vital opportunity to claw their way back into the game, but Tom Kühnhackl's stick imploded as he connected with the puck, thwarting a critical shot on net.

Mannheim sealed the win for Rapperswil after a poorly timed play and turnover saw Czech forward Frk collect, and bury the puck directly infront of an open Mannheim net to make it 4-1 for the host side.

The win marks victory number four for Rapperswil who will now head into the Round of 16 Return game with a three goal lead on aggregate, while German side Mannheim will be under intense pressure to perform or exit.