Former England midfielder Joey Barton made his Marseille debut as the French side rescued a 2-2 draw in a late comeback at Turkish side Fenerbahce.
Barton, on loan from QPR, was taken off on 71 minutes before Marseille scored twice in the final six minutes.
Japan defender Yuto Nagatomo grabbed an injury-time equaliser as Italian giants Inter Milan twice battled back to draw against Rubin Kazan in Group H.
Holders Atletico Madrid won 3-0 at Hapoel Tel Aviv in Group B.
Barton, 30, is banned from playing in Ligue 1 until he serves his 12-match suspension imposed by the Football Association.
He is able to play in the Europa League but it looked to be an unhappy return to action as Marseille trailed 2-0 after 57 minutes.
However, Mathieu Valbuena and Andre Ayew turned the game around after the withdrawal of Barton, who has not played competitively since his red card against Manchester City on the final day of last season.
Liverpool's Group A rivals Udinese and Anzhi played out a 1-1 draw after Antonio Di Natale salvaged a late point for the Italians.
But there were potentially ominous signs for both Newcastle and Tottenham as two of their future opponents recorded comprehensive victories.
French side Bordeaux, Newcastle's next Group D opponents after their 0-0 draw at Maritimo, cruised to a 4-0 win against Belgian visitors Club Brugge.
And Slovenian hosts Maribor, who play Tottenham later in their Group J campaign, stunned Panathinaikos of Greece with a 3-0 success.
Russian side Rubin Kazan looked set to cause a shock at the San Siro when Jose Rondon put them 2-1 ahead with just six minutes of normal time remaining.
But Inter, one of the tournament favourites, ensured they did not lose their opener after Marko Livaja had earlier cancelled out Aleksandr Ryazantsev's opener for the visitors.
Atletico Madrid, without rested star striker Falcao, started their defence in formidable style thanks to goals from Cristian Rodriguez, Diego Costa and Raul Garcia in Israel.
Elsewhere, former England boss Steve McClaren watched his FC Twente side surrender a two-goal lead to draw 2-2 against Hannover, while Israeli minnows Hapoel Kiryat Shmona earned a superb 1-1 draw at last season's beaten finalists Athletic Bilbao.