With the match finishing 1-1 after extra-time, following the same result in the opening leg, the youngster kept his head as PSV triumphed 4-2 in the shoot-out to end a European hoodoo which had seen them lose their last six quarter-finals.
The game exploded into life in the 10th minute as Sylvain Wiltord silenced the home fans by giving Lyon the lead with their first chance of the game.
The former Arsenal striker latched upon a weak headed clearance from Wilfred Bouma and from just inside the penalty area struck a firm right-foot shot which PSV goalkeeper Gomes got a hand to but could not keep out.
Minutes later Wiltord threatened again sending in a dangerous left-wing cross which Gomes smartly cut out.
It was all PSV after the visitors’ opening strike and Park, in particular, was proving a problem to the Lyon defence.
The home side were rewarded five minutes into the second period as Cris gave away a dangerous free-kick on the edge of the Lyon box.
Mark van Bommel swung in the cross to the back post and after another weak clearance, Alex chested the ball down before lashing an unstoppable right-foot drive past Coupet.
This brought the home fans to life and moments later Park flashed a 30-yard drive narrowly over.
Chances were at a premium in the following 20 minutes but a series of Lyon corners saw Cris threaten twice.
Juninho had shown little sign of his devilish ability from set-pieces but his first delivery was met by the defender who fired in a shot that was eventually cleared.
He met the next cross with an acrobatic volley which drifted wide before Jefferson Farfan had an excellent opportunity to give the home team the lead.
The Peruvian was presented with the chance after Coupet could only parry substitute Marcus Beasley’s near-post cross into his path.
But from close range he lost control and the ball rolled harmlessly wide.
The visitors were denied what appeared to be a cast-iron penalty in the 10th minute of the first period of extra-time.
There appeared to be no danger as Juninho chased a ball towards the byline - but PSV keeper Gomes thought differently and appeared to drag him down although Danish referee Kim Milton Nielsen remained unmoved.
In the second period Park and Cocu went close for PSV.
However, the scoreline remained 1-1.
After three successful penalties Gomes saved a weak attempt from Lyon’s midfield talisman Michael Essien.
Coupet saved Beasley’s penalty but Gomes immediately returned the favour repelling Abidal, to leave young substitute Robert to keep a cool head and place the crucial spot-kick into the corner to secure passage through to the semi-finals.
PSV: Gomes, Ooijer, Lee, Alex, Bouma, Van Bommel, Park, Cocu, Vogel, Vennegoor of Hesselink (Beasley 57), Farfan (De Pinho 85).
LYON: Coupet, Cris, Cacapa, Abidal, Reveillere, Diarra, Juninho, Essien, Malouda, Govou (Ben Arfa 87), Wiltord (Nilmar 95).
Ref: Kim Milton Nielsen (Denmark).