The Polish international bagged the lot for the Yellow-Blacks as they beat the men from the Spanish capital 4-1 in a thunderous encounter at the Signal Iduna Park. Lewandowski put the hosts in front in the eighth minute, with Cristiano Ronaldo levelling for Real just before the break. Three unanswered strikes from the home No.9 after the restart, in the 50th, 55th and 67th minutes - the latter a penalty - put the recently dethroned German champs well in the driving seat for the return at the Estadio Santiago Bernabeu.
Great start for BVB
The first chance of what was a high-tempo contest from the off fell to Dortmund six minutes in. After Sven Bender won possession in midfield, Marco Reus surged forward from the centre circle before firing in a low shot that Real custodian Diego Lopez managed to push to the side, Lewandowski failing to capitalise on the rebound. The on-form Polish frontman made no mistake two minutes on from that, however, escaping marker Pepe to get on the end of Mario Götze's pinpoint ball in from the left and slip it past Lopez.
Real enjoyed a decent spell of possession in the wake of the opener, but the hosts were still looking that bit sharper in their passing and more dangerous in the final third of the park, while Bender was doing sterling work keeping Cristiano Ronaldo in check. Midway through the half, the Portuguese superstar got his first sight of goal, firing in a long-distance free kick that pulled a flying save out of home keeper Roman Weidenfeller.
Real pull level
For the most part, though, the men from the Madrid were struggling to find the balance between pressing high up the pitch and keeping Dortmund reined-in when the Yellow-Blacks did the same. Jakub Blaszczykowski's barnstorming run down the right flank needed a crucial intervention from Gonzalo Higuain to prevent the Polish national team captain getting off a shot at close range, as Jürgen Klopp's men switched on the turbo in familiar fashion.
The first-half drama peaked minutes before the break, as Reus had a penalty shout turned down after going to ground in the box following a tangle with Raphael Varane. The Borussia players' protests' had barely ebbed away when they were caught cold. Real broke away down the right, Mats Hummels under-hit a back pass, Higuain pounced on it and slid the ball across to Ronaldo, who duly dispatched his 50th all-time Champions League goal to put a whole new perspective on the contest.
Fast and furious restart
The required medicine for Dortmund after the restart was a quick goal - and Lewandowski provided it five minutes in. Reus took a pot, the ball rolled through to the No.9 and with the Real defence looking in vain for offside, he kept his cool to prod home. 2-1, and it was to get better for BVB and their on-fire frontman in like measure. Five minutes down the line, a cross-shot from Marcel Schmelzer found its way via a deflection to Lewandowski, who shrugged off Pepe before drilling his finish into the roof of the net - and at a stroke becoming the first player to score a hat-trick against Real Madrid in the Champions League.
Far from sitting back, BVB, roared on by the South Terrace they were now playing towards, ramped up the pressure even further. Ilkay Gündogan drilled in a piledriver that Diego Lopez just managed to tip over the bar and then, with 66 minutes on the clock, Xabi Alonso bustled Reus over inside the area and the referee pointed to the spot. Lewandowski - who else? - stepped up to dispatch it high into the net past Lopez.
Dortmund see it home
Real coach Jose Mourinho promptly brought on fresh forward power in Karim Benzema and Angel di Maria and with quarter of an hour to go, Weidenfeller pulled off a crucial interception to a Sami Khedira cutback with Ronaldo ready to pounce for his own second. As Madrid's attempts to give themselves a second-leg lifeline grew ever more desperate with the clock ticking down, Weidenfeller again foiled Ronaldo one-on-one near the finish, to preserve his side's handsome three-goal cushion.
Dortmund: Weidenfeller - Piszczek (Großkreutz 83'), Subotic, Hummels, Schmelzer - Bender, Gündogan (Schieber 90') - Götze, Reus, Błaszczykowski (Kehl 82') - Lewandowski
Real Madrid: Diego Lopez - Ramos, Varane, Pepe, Coentrão - Khedira, Alonso (Kaka 80'), Modrić (Di Maria 68') - Özil, Ronaldo, Higuaín (Benzema 68')
Goals: 1-0 (Lewandowski 8'), 1-1 (Ronaldo 43'), 2-1 (Lewandowski 50'), 3-1 (Lewandowski 55'), 4-1 (Lewandowski 67')