Michael Steele/Getty Images
Challenging Toulouse and Saracens for the title of toughest pool winner to predict comes Leicester Tigers and Ulster, three points apart and with an almighty encounter scheduled for Jan. 18.
Before that, however, the Irish powers must validate their billing as suitable candidates to qualify automatically, hosting a tricky Montpellier side this weekend while the Tigers have a fairly rudimentary run out scheduled against Treviso.
Mark Anscombe's side will be on a high after winning against Munster over the New Year's Pro12 period, but the visit of the Top 14 titans threatens to derail their Heineken Cup bid.
In all likelihood, Richard Cockerill's side will once again claim a bonus point win over their Italian hosts for the second time in succession, but Ulster could very well slip off the pace at Ravenhill.
Regardless, matters will rest on the direct clash between Leicester and Ulster the following weekend, where the English giants have a chance to seal the deal and make the best of what's been a disappointing campaign domestically.
Coping with injuries and the news of Toby Flood's summer departure to Toulouse, per BBC Sport, Leicester will receive a boost thanks to a somewhat surprising win over Anscombe's outfit next weekend.
As long as the Tigers beat Treviso, the worst-case scenario is that they'll be four points behind Ulster come Matchday 6, but it would be highly surprising to see the province claim a bonus-point win over Montpellier this term and an impending loss at Welford Road.