AC Sparta Praha rediscovered their winning touch by beating last season's UEFA Europa League runners-up Athletic Club 3-1 in the Czech capital.
Goals from Tomáš Zápotočný and Bekim Balaj set Vítězslav Lavička's side on their way before Josef Hušbauer's 56th-minute penalty sealed their first Group I points.
Although the first significant opening came in the Sparta area, when Aritz Aduriz tried a back-heel from Óscar de Marcos's pass, it proved a false dawn for Marcelo Bielsa's team on a frustrating evening.
After Václav Kadlec broke through to rattle the woodwork, the hosts went ahead on 25 minutes. Receiving the ball from Marek Matějovský, Zápotočný stepped inside Ibai Gómez's challenge to let fly a powerful swerving effort that Gorka Iraizoz could merely help on its way. De Marco sought to repeat the trick for Athletic, but his strike was rebuffed by Tomáš Vaclík.
In an end-to-end contest, it required a block from Carlos Gurpegi to prevent Balaj slamming in Kadlec's pass from the right. Yet Balaj soon got his first European goal five minutes before half-time, heading Hušbauer's right-wing cross beyond Iraizoz via the face of Aduriz. If the unwitting deflection stung the Athletic forward, it also left his side staring at a fifth successive winless game.
Athletic had at least drawn on matchday one, yet here were Sparta – following four straight defeats, including at Olympique Lyonnais a fortnight ago – on the verge of their Group I breakthrough. It nonetheless took a superb stop by Vaclík, from Gurpegi's flying header, to maintain that position as Athletic seized the second-half initiative.
Despite that response, the Spanish side fell further behind when Xabier Castillo was penalised for catching Kadlec and Hušbauer slotted in the resulting spot kick. If the introduction of substitute Fernando Llorente suggested Athletic would fight on, De Marcos finally rewarded their perseverance with a cool 73rd-minute finish from Iker Muniain's cutback.