Manchester United laboured to a 1-0 Europa League victory over Zorya Luhansk at Old Trafford as Zlatan Ibrahimovic headed home in the second half to seal the points for the below-par hosts.
United struggled to create clear-cut chances against their well-organised Ukrainian opponents, until Jose Mourinho brought on Wayne Rooney, who within moments was involved in the move that brought the 69th-minute breakthrough.
Timothy Fosu-Mensah found space on the right and pulled the ball back towards Rooney, whose miscued effort looped into the air and was headed in by Ibrahimovic from a couple of yards out at the far post.
Fenerbahce saw off Feyenoord 1-0 in the other game in Group A, with Emmanuel Emenike's goal enough to secure the points in Turkey.
After 18 minutes, Fenerbahce opened the scoring when Emenike finished off a swift counter-attack with a powerful effort that flew in off the post.
Mehmet Topal headed wide as the home side looked to extend their advantage, but Feyenoord's former Liverpool striker Dirk Kuyt threatened an equaliser before alert goalkeeping by the visitors' Brad Jones prevented a second-half own goal and the visitors' Bilal Basacıkoglu saw a low effort saved.
Through two games, Fenerbahce top the group on four points, one ahead of Feyenoord and United.
Poor defending cost Inter Milan as the Italian giants suffered their second straight Europa League defeat, 3-1 at Sparta Prague.
The hosts took the lead after just seven minutes when Felipe Melo's attempt at a diving clearance only pushed the ball into Vaclav Kadlec's path.
It got worse for Inter on 25 minutes when the back line was caught napping at a quickly taken free kick, leaving Kadlec plenty of time in the box to double the lead.
Rodrigo Palacio pulled a goal back for Inter with 20 minutes to play, but after Andrea Ranocchia was sent off for a second yellow card, Mario Holek headed home from the resulting free kick to seal the win.
Also in Group K, Southampton stayed top with a goalless draw at Hapoel Be'er Sheva.
Virgil van Dijk put a header from close range over the bar in the fourth minute for the Premier League side, who were fortunate that Maor Melikson's 67th-minute shot rolled just wide of the post.
Mario Balotelli was again on the scoresheet before limping off as Nice fell to a 5-2 defeat at Krasnodar.
After Fedor Smolov and Joaozinho had put the hosts two goals up, Balotelli scored his fifth goal in four games with a sliding shot from the top of the box.
But he was replaced at half-time, and a Joaozinho penalty and late brace from Ari were enough to give the Russian club victory.
Schalke are level with Krasnodar on six points atop Group I after cruising to a 3-1 over Salzburg, thanks to strikes from Leon Goretzka and Benedikt Howedes and a Duje Caleta-Car own goal before Jonathan Soriano's consolation for the visitors.
Fiorentina took the lead in Group J with a 5-1 home win over 10-man Qarabag.
Elvin Yunuszade's red card on the half-hour allowed the Viola to take control with braces from Khouma Babacar and Mauro Zarate, with Nikola Kalinic also on the scoresheet.
Also in Group J, PAOK responded after conceding in the first minute to win 2-1 at Slovan Liberec.
Nikolai Komlichenko provided the hosts the lead seconds into the game before Stefanos Athanasiadis' 10th-minute penalty, and Stefanos Athanasiadis found the winner with eight minutes to play.
Roma rose to the top of Group E with a 4-0 victory over Astra Giurgiu in the Italian capital.
Luciano Spalletti's side, now on four points, went in front a quarter-hour into the first half. Roma legend Francesco Totti's pass from a set-piece situation dropped invitingly onto Kevin Strootman's left foot at the far post, leaving the Dutchman to only guide the ball in from point-blank range.
The Italians saw their lead double moments before the break, and from another set-piece -- Fazio's header from close closing the half on a positive note for the home side.
Roma then added two more after the break through a Fabrício own goal and a Mohamed Salah strike in the 54th minute to round out the rout at the Stadio Olimpico.
Austria Vienna drew 0-0 with Viktoria Plzen in the group's other match. The Austrians, who entered the night atop the table, couldn't capitalise on their home advantage and now sit level on points with Roma in the group.
In Group F, Athletic Bilbao's 1-0 defeat of Rapid Vienna, coupled with Genk's victory, put all four teams even on three points apiece.
Benat bagged the winner in the 59th minute for the hosts, hammering home from outside the box after a fine cushioned headers from Raul Garcia to give the Spanish side the point on the night.
In the other game, Genk were 3-1 winners at home against Italian side Sassuolo.
Nikolaos Karelis nudged the Belgians in front on eight minutes -- the Greece international firing home from just outside the six yards box after a pass from Alex Pozuelo.
Leon Baily then gave Genk their second of the night midway through the half, firing home from the centre of the box in the 25th minute. Thomas Buffel added a third for Genk in the 61st before Matteo Politano collected and insurance strike four minutes later.
Daniel Wass scored from a stunning 30-yard free kick to cap Celta Vigo's 2-0 win over Panathinaikos after John Guidetti broke the deadlock in the 84th minute in Group G.
Ajax won their second straight to top Group G as Kasper Dolberg scored the only goal in a 1-0 home win against Standard Liege.
Villarreal still top Group L after earning a 1-1 draw at Steaua Bucuresti, the Spanish side taking the lead early through Rafael Santos Borre before Sulley Muniru equalised after 20 minutes.
Marco Schoenbaechler scored to make up for a missed penalty and Dzengis Cavusevic netted the winner 11 minutes from time as FC Zurich defeated Osmanlispor 2-1.
Irish side Dundalk continued their surprise start to Group D with a 1-0 win over Maccabi Tel Aviv.
Ciaran Kilduff, who scored Dundalk's equaliser at AZ Alkmaar two weeks ago, finished off a fine assist from Daryl Horgan for the only goal in the 72nd minute.
Aleksandr Kokorin scored twice as Zenit St. Petersburg made it two wins from two with a 5-0 win over AZ Alkmaar.
Kokorin netted in the 26th minute following a fine dummy by striker Giuliano, who got a goal of his own when he lashed home a rebound early in the second half.
Kokorin added his second before the hour mark, Domenico Criscito converted a penalty and Oleg Shatov capped the scoring.
Despite playing the second half with 10 men, Shakhtar Donetsk stayed perfect through two games in Group H with a 2-0 win at home against Braga.
Taras Stepanenko scored five minutes in, and though Fred was sent off for two bookings, Viktor Kovalenko was able to double the hosts' advantage.
Also in Group H, first-half goals from Kenneth Saief and Renato Neto allowed Gent to beat Konyaspor 2-0.
In Group C, Mainz rallied to win at Qabala 3-2 after allowin the Azerbaijan side to score twice in a five-minute span.
Yoshinori Muto had put the Bundesliga side ahead shortly before the break, but Qabala responded with a Ruslan Gurbanov penalty and Sergei Zenjov's strike.
But Jhon Cordoba equalised seconds after coming on, before fellow substitute Levin Oztunali scored the winner to give Mainz their first-ever Europa League victory.
Also in Group C, Saint-Etienne stole a point in a 1-1 draw at home against Anderlecht.
Youri Tielemans's second-half penalty had Anderlecht ahead until stoppage time, when Davy Roef collided with a defender and Nolan Roux capitalised to salvage a draw.
APOEL won again in Group B as Pieros Sotiriou's 10th-minute header was enough to win 1-0 at Olympiakos.
Astana and Young Boys played to a 0-0 draw in the other game in Group B, the Kazakhstan side coming closest when Djordje Despotovic hit the bar with a spectacular overhead effort.