Lulea took the biggest step towards the Quarter-finals by dismantling Czech side Kometa Brno 6-1 in their home leg.
The Swedish champions fell behind less than two minutes into the match, when David Moravec's quick shot flew into the net and silenced the home crowd. But Lulea responded in the second minute of the second period, as Anton Levtchi tucked home a rebound after pressure from the hosts.
The final 20 minutes, however, belonged to Lulea, who went ahead five minutes in when William Hakansson's shot found its way through a crowd, before Brian O'Neill finished well despite a tight angle and Markus Nurmi made it 4-1, squeezing the puck past the goaltender.
Late on Brendan Shinnimin finished off a wonderful attack from one end of the ice to the other, then with four seconds to play, Pontus Sjalin was on hand to poke home another following Hakansson's excellent steal in the attacking zone, as five unanswered goals put Lulea in control of this tie.
The pair will meet again in the Czech Republic on Tuesday with Brno needing a minor miracle to keep their CHL hopes alive.
Frolunda went into their match with Grenoble as favourites having finished third in the CHL league standings, and got the desired result in the away leg, beating the French champions 3-1.
The Swedish Hockey League (SHL) leaders came under some early pressure, but regrouped and took the lead after nine minutes through Jacob Peterson on a powerplay. Jere Innala got an assist, but he failed to add a goal of his own two minutes later when his penalty shot was saved by Matija Pintaric.
The Gothenburg side's failure to extend their advantage came back to haunt them late in the second period when Aurelien Dair equalised for the hosts.
But in the fifth minute of the third, Linus Weissbach set up Isac Heens to restore the advantage, and after surviving for pressure from the Bruleurs de Loups, Frolunda sealed the win when Weissbach skated away and finished well past Pintaric.
The two teams meet again in Sweden on Tuesday and though the tie is still alive, it'll be a tall order for the French side to turn things around at the Scandinavium.
Brynas have given themselves plenty of work to do as they lost their first leg 2-1 at home to SC Bern.
The Swiss side made the breakthrough in the seventh minute of period two when neat play from Marco Lehmann laid the puck on a plate for Benjamin Baumgartner, but Brynas came back in the sixth minute of the third, when Johan Larsson finished off after patient build-up on a powerplay.
It was a very even game, but it went the way of the visitors with six minutes to play, as The Bears forced a turnover in the Brynas zone and Lehmann took full advantage by powering in the winning goal.
Brynas' SHL and CHL form has been inconsistent all season, and they need to find some before Tuesday's return leg in Switzerland.