Jose Mourinho endured frustration on his return to UEFA Champions League action with Chelsea as Basel came from a goal down to win 2-1.
Six years to the day after a 1-1 draw with Rosenborg that represented the final game of Mourinho's first spell in charge at Stamford Bridge, Chelsea were stunned by second-half goals from Mohamed Salah and Marco Streller.
Oscar fired the hosts ahead in the 45th minute in the Group E clash with his sixth goal in seven Champions League outings and the Brazilian also hit the bar prior to Salah’s classy left-footed leveller.
That goal prompted Chelsea to throw men forward, yet it was Basel - always dangerous on the break - who struck again when Streller beat Petr Cech with a near-post header from a corner.
Willian was handed his Chelsea debut and Marco van Ginkel a first start as Mourinho made five changes from the side beaten 1-0 by Everton at the weekend.
Basel recalled a host of players after fielding a weakened side for their Schweizer Pokal victory against Munsingen.
Mourinho's men unsurprisingly started the game on the front foot, albeit without creating any clear-cut opportunities.
There was a scare for Basel goalkeeper Yann Sommer in the 15th minute when he fumbled a corner from the left, but a free-kick was swiftly awarded in his favour.
The pacey Salah - a scorer at Stamford Bridge in last season's Europa League semi-final between the two sides - represented the main threat when Basel launched occasional attacks.
After Eden Hazard had spurned a rare clear sighting of goal for Chelsea following good work from Samuel Eto'o, Salah also proved wasteful when cutting in from the right and curling a shot over the bar.
Despite dominating possession and the corner count, the hosts remained frustrated as half-time approached.
However, Chelsea were lifted on the stroke of the interval as Oscar popped up with a timely goal.
David Luiz set the attack in motion by stepping into midfield and Oscar latched on to a delicate throughball from Frank Lampard to find the bottom-left corner with a first-time shot on the turn.
Streller was close to connecting with a left-wing cross early in the second half before Oscar struck the bar at the other end with a tremendous effort from just outside the area.
Hazard failed to hit the target once again either side of Branislav Ivanovic twice threatening from set-pieces.
Chelsea were then punished for not extending their lead when a cross from the left broke via Streller to Salah, who emulated Oscar by only requiring one touch to find the net.
Although Chelsea poured forward in search of a late winner, it was Basel who finished the stronger and their encouraging play gained reward as Streller shocked the home crowd.
|16||M. van Ginkel||42'|
|Coach: José Mourinho|
for Willian 67'
for F. Lampard 76'
for M. van Ginkel 76'
|Gestede eager to make his mark at Villa|
|I want to play more and score more - Remy|
|Lambert influence important, says Pulis|
|Benteke a ´bargain´ buy - Rodgers|
|Zola: Qatar would be ideal for Balotelli, Cassano|
|Suarez: I´m not among world´s best|
|PSG ready despite ´chaotic´ pre-season - Blanc|
|Arsenal thumping still hurts - Fournier|
|Aubameyang targets Champions League success|
|Rooney set for Everton return|
|Cech can match Van der Sar - Wenger|
|Mourinho ponders Wenger´s losing record against him|
|CBF confirm Fred failed a doping test|
|Bournemouth beaten by battling Cardiff|
|Immobile injury overshadows Sevilla win at Vicarage Road|
|Lambert at the double on West Brom bow|
|Real sign up Spain starlet Vallejo|
|Valencia blow for West Ham|
|Elche cleared to play in Segunda Division|
|Baker pens a new Villa deal|
|Lambert makes Albion switch|
|Gillingham and Scally found guilty of ´race victimisation´|
|Inter complete Jovetic signing|
|Arsenal v Chelsea: Mourinho cools Wenger rivalry ahead of Wembley meeting|
|Villa snap up Gestede|
|Villa land Veretout|
|Mourinho coy on fresh Stones bid|
|Aubameyang commits to Dortmund|
|Torres on the hunt for trophies with Atletico|
|Cazorla and Walcott sign new Arsenal deals|
|Quick start vital in Arsenal title bid - Wilshere|
|I have received no offers - Guardiola|
|Barcelona to monitor Turan injury|
|Zorc ´surprised´ by Grosskreutz-Tuchel row|
|Phil Neville could be England manager - Moyes|
|UEFA to investigate Shakhtar´s Fred selection|
|City loan Unal to Genk|
|China v South Korea: Stielike looking for new options|
|North Korea v Japan: Halilhodzic to unearth new faces|
|Drogba: I want to be ready, not a burden|
|Hamstrung Clasie in doubt for Southampton league opener|
|West Ham goalscorer Zarate bemoans Astra comeback|
|Negredo quashes Valencia exit rumours|
|´This is not my Sampdoria´ - president Ferrero|
|Criscito could join Inter - agent|
|CBF endorse Zico´s FIFA presidency campaign|
|Hawit to handle CONCACAF´s referee review|
|Falcao is a ´top, top player´ - Terry|
|Tuchel pleased by Dortmund fighting qualities|
|Premier League rules out schedule changes for Champions League clubs|
|UEFA Europa League Review: Southampton stroll as Sampdoria are humiliated|
|Koeman confident of Southampton progress|
|Bilic frustrated with Collins´ red card, Valencia injury|
|Bamford hits hat-trick in Bromley friendly|
|Southampton 3 Vitesse 0: Play-offs in sight for Koeman’s men|
|Wolfsberger 0 Borussia Dortmund 1: Tuchel begins tenure with narrow win|
|West Ham 2 Astra 2: Collins red allows visitors back in|
|Kukesi - Legia match abandoned|
|Joining Roma an ´easy decision´ - Szczesny|
|Chiriches joins Napoli from Spurs|
|Mihajlovic pleased with Milan improvements|
|Injured Chiellini to miss Supercoppa|
|Newcastle complete Mbemba swoop|
|Blackpool protest incurs FA fine|
|Scottish Premiership Preview: Dons seek to run Celtic closer|
|Paris Saint-Germain v Lyon: Ibrahimovic ready for season opener|
|Wolfsburg v Bayern Munich: De Bruyne centre of attention|
|Real Madrid 0 Milan 0 (10-9 on pens): Real lift second International Champions Cup|
|De Bruyne a doubt for Supercup clash|
|Reine-Adelaide needs time to blossom, says Walcott|
|Rodgers will not rush Ibe development|
|Napoli not interested in selling Higuain - De Laurentiis|
|Wilson agrees Bournemouth extension|
|Messi makes early Barcelona return|
|Ibrahimovic: My next move will be a very big surprise|
|Van Aanholt backs Lens to shine|
|Besiktas complete loan move for Gomez|
|McClaren: No decision on Coloccini future|
|Kane, Kaka hail goalkeeper Rimando|
|Chung eager to become FIFA president|
|Yedlin open to loan move|
|Tigres not scared of River trip - Ferretti|
|MLS Preview: Wright-Phillips, Lampard set to debut|
|´A draw is good for us´ - River´s Gallardo confident of Libertadores success|
|Di Maria poised for PSG switch - Blanc|
|Franjic: Bring on Bangladesh, Tajikistan|
|Van Gaal bemoans De Gea situation|
|MLS All-Stars 2 Tottenham 1: Kane stunner can´t spare Spurs|
|Manchester United 0 Paris Saint-Germain 2: Van Gaal´s defensive frailties exposed|
|Tigres UANL 0 River Plate 0: Visitors lose Gallardo in Copa Libertadores final first leg|
|Penedo parts ways with Galaxy|
|Benitez backs Mihajlovic, Milan to succeed|
|Barnetta joins Union in MLS|
|Allegri critical of Morata´s attitude|
|Franjic targets more A-League glory with City|
|Beto undaunted by Super Cup clash against Barca|
|Advocaat upbeat despite another Sunderland flop|
|McClaren praises Newcastle recruit Mitrovic|
|Payet will improve West Ham - Bilic|
|Pulis confirms interest in Lambert|
|Deila expects tough test in Baku|
|Drogba mobbed by Montreal Impact fans|