On the final matchday in Groups C, D, G and H, Guangzhou were joined by a host of clubs in the last 16 on Tuesday, but it was their progression that made the headlines after a nervy campaign to date.
Marcello Lippi's side - who have won the last three Chinese Super League titles - did not have their place in the next stage confirmed until their win over the J.League side.
All four sides headed into their final Group G match with a chance of progressing, and a first-half double from Brazilian Elkeson proved enough for the Chinese giants.
Manabu Saito's 85th-minute effort for Yokohama created a tense finish, but the hosts did enough to hang on, with the result seeing the losers finish bottom of the group.
Melbourne Victory missed out on goal difference only, after their 0-0 draw at K-League outfit Jeonbuk Motors, who progressed in their place.
In Group H, the Western Sydney Wanderers finished top after a 5-0 rout of Guizhou Renhe of China.
The A-League side took the lead in the seventh minute through Shannon Cole, before four goals in the last 15 minutes capped off a five-star performance.
Labinot Haliti, Aaron Mooy, Shinji Ono and Nikolai Topor-Stanley were the players to score late as Tony Popovic's side reached the last 16 in their first ever Champions League campaign.
They finished goal difference ahead of Japan's Kawasaki Frontale, who beat Ulsan 3-1 in the other match.
Al Ain and Al Ittihad progressed from Group C after a 1-1 draw, while Madjid Bougherra's second-half penalty helped Lekhwiya to a 1-0 win at Tractor Sazi in an ultimately meaningless match.
And in Group D, Al Hilal and Al Sadd - who started the day in third and fourth respectively - moved into the last 16 after home wins.
Al Hilal beat Sepahan 1-0 thanks to Nasser Al Shamrani's goal, while Al Sadd came from behind to defeat Al Ahli 2-1.
