Mourinho joked that Arsenal's medical team had performed an "amazing" feat by turning Lacazette "from a no to a complete 90 minutes".
Elsewhere, Roma recorded a 1-0 win over Qarabag at the Stadio Olimpico.
Group winners are drawn against second place sides and play away first, with the second legs at home.
Kylian Mbappe calmed PSG nerves five minutes after the restart when he put the finishing touch to a fine move involving Marco Verratti and Edinson Cavani, but Tolisso made it 3-1 with 21 minutes remaining.
When will the matches be played?
In Group D, Barcelona - who had already guaranteed to top their group - defeated Sporting Lisbon 2-0.
The four teams to have secured second spot on Tuesday were Basel, Bayern Munich, Chelsea and Juventus.
The first leg games will be split over two weeks on the 13th and 14th of February with the remaining ties being playe don the 20th and 21st.
Champions League action will continue Wednesday evening when the teams' fates in the last four groups will be decided. Liverpool, Sevilla and Spartak Moscow could all still top Group E.
The round of 32 draw takes place on Monday and will be streamed live in UEFA.com's DrawCentre from 13:00CET.