Strikes from subsitutes Genki Haraguchi and Timo Baumgartl brought the curtain down on 1. FC Union Berlin's preparations for the new season with a 2-1 victory over Athletic Bilbao.

Despite Marcelino's side holding on to a half-time lead courtesy of Alex Berenguer's goal, Urs Fischer's side battled back after the break. In front of over 8,000 supporters at the Stadion An der Alten Försterei, there was something to smile about for the fans who haven't cheered on their side at home in 18 months.

The experienced Genki Haraguchi fired home a superb strike from 25 yards after 75 minutes to equalise against last season's Spanish Cup winners. Six minutes later, the turnaround was complete when Timo Baumgartl headed past Julen Agirrezabala from close range.

1. FC Union Berlin: Luthe (Rönnow 45); Puchacz (Gießelmann 45), Trimmel (Ryerson 60), Friedrich (Jaeckel 70), Knoche (Van Drongelen 70), Khedira, Ingvartsen (Baumgartl 45), Andrich (Haraguchi 60); Endo (Wszolek 60), Voglsammer (Öztunali 60), Awoniyi (Behrens 60)

Athletic Bilbao: Agirrezabala; Morcillio (Lekue 46), Martinez (4), Williams (Villalibre 62)), Berenguer (Serrano 63), Garcia (Vesga 70), Sencet (Capa 46 (De Marcos 62)), Balenciaga (Paredes 70), Vencedor (Williams 46), Vivian (Zarraga 46), Petxarroman (36)

Max Kruse and Cedric Teuchert were among the squad presented to the supporters at te Alte Försterei an hour before kick-off following their time at the Olympics in Tokyo. Union started in a 4-3-3 with Keita Endo, Andreas Voglsammer and Taiwo Awoniyi in attack. Urs Fischer's two wide forwards combined after a superb, defence-splitting pass from Marcus Ingvartsen. Endo charged down the right-hand side, crossed quickly for Voglsammer who looked set to hit the net but Athletic Bilbao got bodies back in time. The team from the Basque region showed their abilities after a strong start from the home side. Left-back Jon Gestoso Morcillio was impressive for the visitors and he came up with the first step, a long-range strike which went over Andreas Luthe's goal. Uncharacteristically for Urs Fischer's side, the next opportunity for Bilbao fell from a set-piece which was not strongly defended. Inigo Berridi Martinez attacked from the back-post and shot into the side-netting after 18 minutes. Morcillio was involved a minute later, setting up a shot for Unai Paris Vencedor but the midfielder shot wide. Despite Bilbao's strengths going forward in the full-back areas, Union managed to find space in behind. Voglsammer and Endo switched sides for a spell, the former Bielefeld striker crossing brilliantly for the Japanese attacker but he headed wide on the slide. On 28 minutes, Athletic Bilbao rattled the ball against Luthe's post with Morcillio again key to the creative part. The defender slotted the pass into the path of Oihan Sencet but he watched on as the ball struck the post and trickled wide. Marcelino's team did break through after 32 minutes with Belengeuer beating Puchacz one-vs-one and then bending his finish in past Luthe from close range. Union's best opportunity brought them close to equalising before the interval. Ingvartsen's quality was on show again but Voglsammer struck at Agirrezabala who protected his first-half clean sheet.

Summer signing Frederik Rönnow pulled on the Union shirt for the first time as a half-time substitution, replacing Luthe. The two other changes went as planned with Timo Baumgartl and Niko Gießelmann taking the places of Tymoteusz Puchacz and Ingvartsen. Part of Denmark's squad at the Euros, Rönnow has only started to get comfortable with life in Berlin and he looked up to the job early on. Inaki Williams broke in behind for Bilbao and fired a decent shot on target - only for the goalkeeper to hold it cleanly. Julian Ryerson, Genki Haraguchi, Pawel Wszolek, Kevin Behrens and Levin Öztunali were given the nod on the hour. The Bundesliga club should have levelled on 68 minutes when substitute Wszolek delivered a great ball into the six-yard box. First Kevin Behrens tried to put the ball in and then Niko Gießelmann was unable to get his body close enough to the ball to turn home. Rönnow saved from Serrano a minute later as spaces emerged behind the Union defence - the Dane again in the right place and making a fine save. The last 20 minutes were a chance for Union's other defensive options to get minutes under their belts with Ricky van Drongelen and Paul Jaeckel taking up the centre-back roles. With 15 minutes remaining on the clock, Union drew level. Athletic Bilbao couldn't clear the deflected effort from Niko Gießelmann's free-kick, the ball landing as far as Haraguchi around the 25-yard range and the Japan internationalist fired powerfully into the net to score his first at the Alte Försterei. It took all of six minutes for the Köpenick club to turn the score around, Haraguchi once again key to the attack. Niko Gießelmann put in the decisive cross and centre-back Baumgartl found himself in the box, but didn't pass up the opportunity, finishing off with a fine header. Perhaps the biggest applause of the night was held back for Anthony Ujah who was given the chance to mark his return from injury with five minutes to play.

And with the 90 minutes at the Stadion An der Alten Försterei, 1. FC Union Berlin's pre season schedule is brought to a conclusion. Next weekend, Urs Fischer's side begin competitive action with a trip to Türkgücü München in the first round of the DFB Pokal. The match will take place at the Grünwalder Stadion in Munich and kick-off is 15:30 on August 8.