Pernille Harder scored against her old club as Chelsea survived an onslaught to beat Wolfsburg in their Champions League quarter-final first leg.
The German side twice hit the post and saw Ewa Pajor's overhead kick cleared off the line as Chelsea looked fragile.
But Emma Hayes' side led when Sam Kerr rounded Katarzyna Kiedrzynek to score and Harder slotted a second after the Wolfsburg keeper gave the ball away.
Dominique Janssen got an away goal from the spot but Chelsea held firm to win.
Both legs of the last-eight tie are being played in the Hungarian capital Budapest because coronavirus travel restrictions in Germany prevent the two-time Champions League winners from travelling to the UK.
Chelsea will be the away team for the second leg next Wednesday, knowing they will reach the semi-finals of the competition for a third time if they avoid defeat.
Blues hold nerve to end hoodoo
Three of Chelsea's four previous European campaigns have been ended by Wolfsburg - most recently in the 2017-18 semi-finals - and the Women's Super League champions had failed to beat the German giants in their six previous meetings, losing five of them.
This one looked like going the same way for large parts - Alexandra Popp prodding against the inside of the post and having a goal disallowed for a blatant handball, while Chelsea goalkeeper Ann-Katrin Berger made an excellent double save before Pajor's acrobatic effort was kept out by the head of Jonna Andersson.
The second half started in the same manner, Fridolina Rolfo's powerful header striking the post, but completely against the run of play Chelsea scored with their first attempt on target and turned the game.
Fran Kirby and Kerr have already combined for eight WSL goals this season and the combination struck gold once more, Kirby helping Ji So-yun's pass on first time to the Australia striker, who finished high into the net from a tight angle.
The excellent Berger tipped over Rolfo's point-blank volley but the Blues then doubled their advantage, Kiedrzynek's short goal kick seized upon by England's Kirby, whose pass to Kerr found Harder who provided a low, calm finish.
The Denmark forward kept celebrations to a minimum against the club where she spent three years before leaving for London in September.
Last year's Champions League runners-up and German champions Wolfsburg were handed a late lifeline when Magdalena Eriksson clattered Svenja Huth in the box and former Arsenal defender Janssen fired the resulting penalty into the top corner.
The last 20 minutes were tense for Chelsea, who saw boss Emma Hayes booked for her complaints after Berger and Popp collided, but they held their nerve and have something to hold on to in the second leg next week.
'We've closed the gap'
Hayes said she was pleased they had ended their winless run against Wolfsburg but felt the German side had an advantage going into the second leg.
"We've closed the gap, which is what my first curiosity was, we've definitely closed the gap," the 44-year-old said.
"They're still a top team, they're still unbelievable in the air and good down the sides, good from restarts.
"I learnt that you have to suffer in moments, but the first leg is always about staying in the tie, that's what it is, there's no home advantage for either team, and I'm left feeling like the advantage is with them, because they've got the away goal.
"I thought we were spirited, with a lot of good performances from us, and the realities are that's a team that's been well-developed over a number of years, so for anybody to think this was going to be an easy tie for them, it's not. We gave them a game and I'm happy about that."
Hayes was also delighted with the contribution of Kirby and Kerr.
"Every week we're talking about one of our players in such a fantastic way which makes me smile," she added.
"One week it will be one, next week, the next. Everybody knows the pressures both Sam [Kerr] and Fran [Kirby] are under but what a joy they are to watch.
"The way they play together, I thought Sam was unbelievable tonight. If you asked her if she enjoyed it she will say 'yeah, I loved that.' She enjoyed being on the biggest stage and showing why she is one of the very best in the world."