Chelsea were one of the sides to take a three-goal lead to the second leg after beating Real Sociedad 5-2 at home.
Having fallen behind just seven minutes into the match, the Blues tied things up later in the half. Veerle Buurman gave the hosts their first lead of the match shortly after the restart, only for Cecilia Marcos to restore parity minutes later.
The 2020/21 finalists showed their experience, with substitute Melvine Malard netting twice while Lauren James also found the back of the net to put them in a strong position for next week's decider.
Chelsea have played in the group phase of the Women's Champions League in all five previous seasons since its introduction in 2020/21. Sociedad, meanwhile, are participating in Europe for just the second time, having lost at this stage in 2022/23.
Wolfsburg enjoyed a 2-0 success over 10-woman Inter Milan as they near a return to the league phase. Lara Prasnikar and Camilla Kuver were the goalscorers for the Germans, who are one of two former winners of the competition to partake in this season's qualifiers.
Wolfsburg have beaten Italian opposition in all four previous two-legged ties in UWCL play, having gotten past Juventus in last season's knockout round play-offs.
Speaking of Juve, they were also among the winners on Wednesday, getting past St. Polten 3-0 away.
Tatiana Pinto scored in either half for the Bianconere, who, like their opponents, have reached the group phase in four of the five seasons so far.
Real Madrid got past Ajax 2-0 in the Netherlands, while Eintracht Frankfurt drew 1-1 with Paris Saint-Germain.
Both goals in Germany came within the first 10 minutes as Frankfurt, four-time winners, outshot PSG 15-7 in the match.
As for Real, they and Chelsea are looking to join Bayern Munich, Barcelona, and OL Lyonnes as the only teams to partake in every group stage/league phase of the UWCL.
Leuven take commanding lead
In the champions path, OH Leuven enjoyed a 4-1 away win against Czarni Sosnowiec as the Belgian champions are 90 minutes away from playing in the league phase for the second season running.
Klaudia Milek gave the Polish side hope as she cancelled Kadhiya De Ceuster's opener. But Leuven did not panic, as Isabella Dekker's five-minute brace in the second half making the difference.
Sosonwiec are the only side to reach this stage of the Women's Champions League from the first qualifying round. They are the only one of the 18 sides in this round looking to become their country's first representatives in the UWCL proper under the group phase era.
Sparta Prague defeated Servette 3-2 in Czechia in a high-scoring encounter. The home side, semi-finalists in the inaugural UEFA Women's Cup last term, are aiming to qualify for the league phase for the first time. They fell at the final hurdle of qualifying three times.
Switzerland's Servette made the group stage in 2021/22, but lost to AS Roma the last round of qualification two years ago.
HB Koge are 90 minutes away from participating in the group phase for the second time after edging PSV 1-0.
Tuesday's only match saw Brann defeat Austria Wien 2-1 after Lauren Davidson scored just past the hour mark to give the Norwegians a narrow lead. The second leg will also be on Tuesday next week.
Next Wednesday will have the other eight return legs, with the nine winning sides joining the nine direct entrants in the league phase. The draw for that round will occur on 4 September.
The nine losing teams will enter the second qualifying round of the UEFA Women's Europa Cup, joining the 11 losing sides from the second qualifying round mini-tournament finals, as well as the 12 winners from the UWEC's first qualifying round.
Follow the final round of UEFA Women's Champions League qualifying action on Flashscore.