Bayer's claims to being Germany's third-best team are under threat. Tuesday's loss to Atletico signalled what could be the start of a very big slide.
Even playing a man up, Massimo Allegri says Porto threatened all match, and Juve had to bide their time to score.
Juventus easily dispatched Porto away from home, while Sevilla took a 2-1 win over Leicester, who grabbed a key away goal.
The ESPN FC panel answer the latest crop of twitter questions, including Shaka's birthday and UCL comebacks.
With all first-legs of the UCL Round of 16 over, the FC panel debate who holds the mantle of tournament favourite.
Miralem Pjanic revealed Juventus boss Massimiliano Allegri urged his players to stay calm as they eventually broke down Porto's 10 men to take control