Glasgow City will face Barcelona, the fourth highest-ranked team left in the competition, in the last 16 of the Womens Champions League.
The Scottish champions, who were unseeded in the draw made in Nyon, will travel to Spain for the first leg on 17 or 18 October.
Barcelona, runners-up in Spain behind Atletico Madrid, will travel to Glasgow on 31 October or 1 November.
Dutch midfielder Lieke Martens, who was named player of the tournament at Euro 2017, is among her team-mates.
Barcelona have finished second in the Spanish top flight for the last three seasons and were edged out by one point by Atletico last season.
They will be bidding to reach the quarter-finals for the fourth consecutive season and lost to eventual winners Olympic Lyonnais 3-1 on aggregate in the last eight last term.
Fran Sanchezs team were given a fright by Kazygurt, who beat City on away goals in last seasons round of 32, at the same stage this season.
City qualified for the last 16 for the first time since 2014/15 after beating Cypriots Somatio Barcelona over two legs.
Scott Booths side entered the competition in the group stage, finishing first ahead of Belgians Anderlecht, Polish champions Gornik Leczna and Martve of Georgia.
This is the fourth time they have made it as far as the last 16, reaching the quarter-finals once, in 2014/15.
For City, there was relief at avoiding a tie with Lyon, the holders, in the seeded draw. Yet the Scottish champions will have their work cut out when they meet Barcelona, who are the fourth highest ranked side left in the competition.
Read more City, who are one of three survivors from the qualifying round, reached the fourth round for the fourth time after defeating Somatio Barcelona of Cyprus in the round of 32. Scott Booths side will travel to Barcelona, who finished second behind Atlético Madrid in Spain last season, for the first leg on 17 or 18 October. The second leg will take place on 31 October or 1 November.
Barcelonas squad contains top talents such as Englands Toni Duggan and Lieke Martens, who was named the player of the tournament when she helped the Netherlands win Euro 2017.
Chelsea are looking for another strong performance in Europe after losing to Wolsfburg in their semi-final last season. But despite thrashing SFK 2000 Sarajevo 11-0 on aggregate in the round of 32, they will not take anything for granted against Fiorentina, who have the second lowest coefficient in the competition.
The unseeded Italians are not to be underestimated after knocking out Fortuna Hjorring, one of the seeds, in the round of 32. The first leg will take place at Kingsmeadow, where Chelsea will hope to make the most of home advantage before travelling to Italy for the return game.
Emma Hayess side are Englands last remaining representatives in the Champions League after Manchester Citys disappointing defeat to Atlético last week. The Womens Super League champions have made a slow start to their domestic campaign, picking up six points from their first four matches.
But after starting with three consecutive goalless draws, Chelsea picked up their first WSL win when they beat Brighton & Hove Albion on Sunday. Fran Kirby scored the opener as the west Londoners rose to fifth place.
Lyons defence of their title will continue when they face Ajax. Wolfsburg, beaten finalists last season, have an awkward test against Atlético.