Daniel Parejo cancelled out Dušan Vlahović's opener after 33 seconds to rescue the hosts.
Dušan Vlahović marked his much-anticipated UEFA Champions League debut with a goal after just 33 seconds for Juventus, but Daniel Parejo hit back in the second half to leave this round of 16 tie delicately poised.
1' Vlahović scores on Champions League debut
13' Lo Celso hits the woodwork
66' Parejo turns in equaliser
Match in brief: Parejo spoils Vlahović's dream debut
It took just over half a minute for Vlahović to silence the home crowd, as the 22-year-old Juventus striker lived up to his billing, expertly bringing a long ball under control before squeezing it into Gerónimo Rulli's far corner.
Advantage Juve, and their January signing could pride himself on recording the quickest ever Champions League goal from a starting debutant – and becoming the first player born this century to score for the Bianconeri in the knockout phase.
Villarreal appeared shaken, and when Giovani Lo Celso found the ball at his feet inside the danger zone in the 13th minute, the Argentinian could only strike the post. Even so, Unai Emery's side began to recoup possession, as Massimiliano Allegri's men set up to sit deep and fend off the hosts' endeavours.
The black-and-white defensive blockade was eventually breached midway through the second period, when Parejo sprung from deep to meet Étienne Capoue's perfectly weighted ball and swept home to set up a fascinating second leg in Turin.
PlayStation® Player of the Match: Daniel Parejo (Villarreal)
"For his second-half performance. He scored a crucial goal, got on the ball and began to control proceedings to get his team back in the game. He showed good responsibility as a leader in his team."
UEFA Technical Observer panel
Joseph Walker, Villarreal reporter
A case of a job well done for Villarreal. The night had potential to turn into a disaster following such a poor start, but Unai Emery's side stuck at it and you have to say they deserved something from a game that was more of a tactical battle than an end-to-end classic. They had a few chances and will take heart for the second leg, but at times it can appear they need a clear-cut chance to score from, as opposed to a half-chance, which may end up costing them.
Paolo Menicucci, Juventus reporter
Juventus failed to capitalise on their early opener, allowing Villarreal to equalise in the second half through a defensive error. The Bianconeri probably renounced their desire to attack too early on, focusing mainly on controlling Villarreal's advances – which did not seem wise – without looking to counter as they did so dangerously in the first half. Still, the Bianconeri are in a good position to qualify ahead of the return leg in Turin, especially given Vlahović's form and the possible return of some key players who were missing tonight.
Massimiliano Allegri, Juventus coach: "We made a bad mistake on their equaliser; we knew perfectly that they were trying that move and we still allowed them to score. However, the team played a good game in general. We also made a few mistakes in attack, straying offside when we had good chances on the counterattack. In general, I'm quite satisfied with the performance."
Dusan Vlahović, Juventus striker: "It was huge to score on my debut; it was very emotional. However, I cannot be 100% satisfied because we have not won the game. We have to keep working hard. We played a good game and we could have won. There are some regrets, but we must just focus on the next game."
Unai Emery, Villarreal coach: "We didn't get scared and we showed our maturity. We could've drawn level in the first half but got what we deserved in the second [...] We conceded, but the side bounced back, drew level and we wanted to win. We need to go to Turin and win."
Owen Hargreaves, BT Sport
"[Vlahović's goal] was class: everything about it – the run in behind and the touch – was first class. Pretty good for your first touch in the Champions League. Once Juventus scored early, they sat back and just absorbed pressure. Villarreal had to try to find a way to score."
Daniel Parejo, Villarreal midfielder: "I thought we were dominant in the first half and in general we deserved to win, given how the game went and that we were the better side. I'm not entirely happy because we played well and went toe to toe with them, and if one side deserved to win it was Villarreal."
• Dušan Vlahović has become the first player born this century to score for Juventus in the Champions League knockout phase.
• Scoring after 33 seconds, Dušan Vlahović recorded the quickest ever goal from a starting Champions League debutant.
• Villarreal's two previous home games in the Champions League round of 16 also finished 1-1: against Rangers in 2005/06 and Panathinaikos in 2008/09.
• Villarreal are unbeaten in their last six home matches in the knockout phase of the Champions League; however, five of those matches have ended in draws (W1 D5).
• Juan Cuadrado has now made 50 Champions League appearances. All but one of those outings have been as a Juventus player, the sole exception coming with Chelsea in 2015.
Daniel Parejo – 11
Danilo – 7
Dušan Vlahović – 6
Étienne Capoue – 6
Villarreal: Rulli; Foyth, Albiol, Pau Torres, Pedraza (Estupiñán 79); Chukwueze (Yeremi Pino 90), Capoue, Parejo, Moreno (Trigueros 79); Lo Celso, Danjuma (Dia 90)
Juventus: Szczęsny; De Sciglio (Pellegrini 87), Danilo, De Ligt, Alex Sandro (Bonucci 46); Cuadrado, Locatelli (Arthur 71), Rabiot, McKennie (Zakaria 81); Vlahović, Morata