( CNN ) -- Do you believe in second chances ? It would appear that those wearing the green and white of Celtic do . Having been handed a brutal beating by Polish side Legia Warsaw in the third qualifying round of the Champions League , Celtic 's European adventure appeared to be over before it had started . A 4-1 defeat in the Polish capital was followed by a 2-0 home defeat -- a result which should have sent Legia through to the playoff stage . Except it did n't . Instead , UEFA , the game 's European governing body , was called in to rule over claims Legia had fielded an ineligible player during the tie . Bartosz Bereszynski , who entered the action with two minutes of the second leg remaining , was supposed to be serving a ban . It was his presence on the field which meant UEFA awarded the game to Celtic 3-0 , making it 4-4 on aggregate and allowing the Scottish champion to progress on away goals . While Legia protested , even taking their failed case to CAS , the Court for the Arbitration of Sport , Celtic ensured it made the most of it fortune . A game against Slovenian champion Maribor was Celtic 's reward with the opportunity to play some of European football 's biggest names the prize . Celtic , which won the European Cup in 1967 , took the lead within six minutes of the kickoff when Callum McGregor fired home from close range after Jo Inge Berget 's effort was diverted into his path . Maribor , which last reached the group stage of the tournament in 1999 , overcame Maccabi Tel Aviv 3-2 on aggregate in the previous round . And it soon carved Celtic open to claim a deserved equalizer when Damjar Bohar ran through to slot the ball past the onrushing Craig Gordon . Both teams had opportunities to win the game with Charlie Mulgrew and Virgil van Dijk going close for the visitors , while Tavares ' rasping effort flew just over the crossbar for Maribor . The two will meet again next Tuesday with Celtic now the firm favorite to progress following the 1-1 draw . Elsewhere , Porto , the 2004 champion , gained an impressive 1-0 win at French side Lille . Hector Herrera 's 61st minute strike was enough to give Porto a slender advantage going into next week 's second leg . In Belgium , Oleg Shatov scored the only goal of the game as Zenit St Petersburg recorded a 1-0 away win at Standard Liege . In the night 's other games , Slovan Bratislava drew 1-1 with BATE Borisov , while Aalborg and Apoel finished 1-1 .
Celtic draw 1 - 1 by Slovenian side Maribor in Champions League qualifier . Scottish side will play second leg next Wednesday . Celtic qualify after Inter Warsaw was thrown out of competition . Porto claims 1 - 0 win at Lille .