Istanbul Basaksehir pulled off a shock 2-1 win over Manchester United in their Champions League clash.
Ole Gunnar Solskjaer's men had been using European fixtures as a welcome distraction from domestic troubles in the Premier League, beating Group H rivals Paris St Germain away and then trashing RB Leipzig 5-0 at Old Trafford.
The Turkish champions went ahead in the 13th minute when Ba found himself given the freedom to collect a long ball and run from the halfway line before slotting past Dean Henderson.
Captain Edin Visca added a second five minutes ahead of the interval after Deniz Turuc had robbed Juan Mata to break down the left.
Although Anthony Martial reduced the deficit before half-time, the home side – with former United defender Rafael in the backline – remained resolute to record a memorable victory.
RB Leipzig beat PSG 2-1 at the Red Bull Arena, where the visitors had two men sent off.
The French side went ahead through Angel Di Maria after six minutes, but then had a penalty saved.
Christopher Nkunku equalised just before half-time, with Emil Forsberg putting the Germans ahead from the penalty spot after 57 minutes.
PSG midfielder Idrissa Gueye was sent off for two yellow cards, with defender Presnel Kimpembe also seeing red in stoppage time.
Barcelona maintained their 100 per cent record in Group G with a 2-1 win over Dynamo Kyiv.
Gerard Pique headed in a second with 65 minutes gone following a corner.
Dynamo captain Viktor Tsygankov reduced the deficit with 15 minutes left, knocking in a rebound.
Alvaro Morata scored twice as Juventus won 4-1 at Ferencvaros.
Cristiano Ronaldo was back in the side following his recovery from coronavirus, which saw the Portugal forward miss the defeat by Barcelona.
Morata put the Italians in front after seven minutes and curled in another on the hour.
Paulo Dybala tapped in a third with 18 minutes left, before an own goal from Lasha Dvali completed the scoring for the visitors. Franck Boli netted a late consolation.
In Group E, Timo Werner scored twice from the penalty spot as Chelsea beat Rennes 3-0 at Stamford Bridge.
The Blues, missing Kai Havertz following his positive test for Covid-19, went ahead 10 minutes in when Werner converted from 12 yards after being brought down by Henrique Dalbert.
German forward Werner added another spot-kick five minutes before the break, which was given after VAR review with Rennes defender Dalbert shown a red card following a second caution for handball.
Tammy Abraham slotted home a third goal early in the second half after a break by Reece James.
Sevilla also have seven points from three games after coming from 2-0 down to beat Krasnodar despite playing the second half with 10 men.
The Russians had raced into a two-goal lead inside 20 minutes through Shapi Suleymanov's goal and a penalty from Marcus Berg.
Ivan Rakitic pulled a goal back just before half-time, with defender Jesus Navas shown a straight red card for a late tackle.
The Spaniards, though, turned the match around when Youssef En-Nesyri struck twice in the space of three minutes to win 3-2.
A double from Erling Haaland helped Borussia Dortmund win 3-0 at Club Brugge.
Thorgan Hazard set the Germans on their way after 14 minutes, with Haaland soon making it 2-0 and then wrapping things up with another goal after 32 minutes.
Earlier, substitute Felipe Caicedo had scored a late equaliser as Lazio drew 1-1 at Zenit St Petersburg.
Alexandr Erokhin put the Russians ahead after 32 minutes, which looked to have been enough for a first group-stage win, before Caicedo struck with just eight minutes left.
There was more late drama as Andrei Mostovoy saw his strike in stoppage time ruled out for an offside in the build-up.