Former Real Madrid and Juventus striker Alvaro Morata ended a miserable spell of form with the only goal of the game on Thursday as Chelsea recorded its second straight 1-0 victory in the Europa League, against plucky Hungarian side Vidi.
Elsewhere, substitute Patrick Cutrone netted twice in nine minutes to lift AC Milan to a 3-1 comeback triumph at home to Olympiakos, while teenage forward Emile Smith Rowe scored his first senior goal as Arsenal made the most of its longest-ever trip for a European game by winning 3-0 at Qarabag.
Like Chelsea, Milan and Arsenal, last year's semifinalist Salzburg, Bayer Leverkusen, Zurich, Sporting, Frankfurt, Krasnodar and Dinamo Zagreb also made it two victories from two group games.
Arsenal's Armenia forward Henrikh Mkhitaryan was one of three players who didn't make the 4,000-kilometer (2,486-mile) trip to the Azerbaijan capital of Baku.
Azerbaijan and Armenia are in a territorial dispute over the Nagorno-Karabakh region.
Mkhitaryan also skipped a trip to Azerbaijan three years ago when he was playing for Borussia Dortmund, with the German club citing security concerns.
Arsenal manager Unai Emery said Mkhitaryan "cannot travel here." It's not clear what will happen if the team reaches the final in Baku.
Here's a look at Thursday's games:
MORATA ON TARGET
Spain forward Morata scored his first goal since August, and only his second of the season, when he swept the ball in from close range following a header from Brazil playmaker Willian, to earn Chelsea maximum points against Vidi.
Substitute Ross Barkley then almost made it 2-0 when his header hit the crossbar a few minutes later.
Chelsea dominated but Vidi defended stoutly and occasionally threatened on the counter attack, forcing two stunning saves from goalkeeper Kepa Arrizabalaga in front of the watching Hungarian Prime Minister Viktor Orban.
"I'm really very happy for Morata," Chelsea manager Maurizio Sarri said. "It's very important for him to play for the team like he did this evening. He has to take confidence from his performance."
With three goals early on, PAOK Thessaloniki cruised to a 4-1 win at BATE Borisov.
BATE and PAOK trail Group L leader Chelsea by three points.
MILAN FIGHTS BACK
Boosted by a 4-1 victory at Sassuolo in Serie A on Sunday and with forward Gonzalo Higuain returning from injury, seven-time European Cup champion AC Milan looked strong in the opening stages against Olympiakos and had an offside goal disallowed early on.
Miguel Angel Guerrero gave the visitors the lead against the run of play in the 14th minute with a deflected header.
Milan then wasted some chances before Ricardo Rodriguez crossed for Cutrone to head the equalizer with 20 minutes to go. Higuain's low shot put the Italian club 2-1 up and Cutrone tapped in his second goal from close range in the 79th.
Milan leads Group F with six points, two ahead of Real Betis, which scored three goals in the second half to ease past Luxembourg newcomer Dudelange 3-0.
ARSENAL NINE RESTED
Emery followed the example of predecessor Arsene Wenger by resting nine front-line players in Baku.
Pierre-Emerick Aubameyang, who netted twice in the opening 4-2 victory over Vorskla, didn't travel due to illness, while Aaron Ramsey stayed at home for family reasons.
Sokratis Papastathopoulos scored the first goal after four minutes when Nacho Monreal headed the ball on from a corner. The 18-year-old Smith Rowe and Matteo Guendouzi then struck in the second half.
Sporting rallied to win 2-1 at Ukraine's Vorskla to join Arsenal atop Group E with six points.
LAZIO PAIR SENT OFF
Lazio's Dusan Basta and Joaquin Correa were sent off in their team's 4-1 defeat at Eintracht Frankfurt.
Basta received a second yellow card at the end of the first half, while Correa was dismissed for a challenge on Jonathan de Guzman in the 58th minute.
Danny da Costa (2), Luka Jovic and Filip Kostic were on target for Eintracht, with Marco Parolo replying for Lazio.
A late goal from Emilio Zelaya salvaged a 2-2 draw for Apollon Nicosia at home to Marseille after last year's runner-up had led 2-0.
Eintracht tops Group H with six points, three more than Lazio.
OTHER GROUPS
Sevilla lost 2-1 at Krasnodar in Group J. The most successful club in Europa League history went ahead after Charles Kabore's own goal but the Russian side rallied thanks to Mauricio Pereyra and Tornike Okriashvili.
Bayer Leverkusen came from a goal down to defeat AEK Larnaca 4-2 and is tied atop Group A on six points with Zurich, which edged Ludogorets 1-0.
In Group B, Salzburg came from a goal down against Celtic to win 3-1 and now leads the way on six points. The Scottish champion is tied in second place on three with Leipzig, which won 3-1 at Rosenborg.
Dinamo Zagreb upset host Anderlecht 2-0 to dominate Group D with six points.
Rennes had to travel even further than Arsenal, 5,000 kilometers (3,107 miles), to Kazakhstan's Astana and suffered a 2-0 defeat in Group K.
Rangers, managed by former England midfielder Steven Gerrard, won 3-1 at home to Rapid Vienna with two goals from Alfredo Morelos and a penalty by James Tavernier. Also in Group G, Spartak Moscow drew 3-3 with Villarreal.
Newcomer Sarpsborg beat Genk 3-1 in Group I to claim its first Europa League victory.
