Radu Dragusin's early dismissal was no obstacle for Ange Postecoglou's side, who cruised to victory at the Tottenham Hotspur Stadium thanks to goals from Brennan Johnson, Pape Sarr and Dominic Solanke.

However, the sight of South Korea forward Son being forced off in the 70th minute will be concerning for Postecoglou, who cannot afford to be without his talismanic captain for a long period.

With a healthy Son, the Europa League could offer a path to silverware for Postecoglou, who boasts that he always enjoys success in his second season as he seeks to end a Tottenham trophy drought dating back to 2008.

Sterner tests await Tottenham but they delivered a confident opener, once the game -- delayed for 37 minutes after Qarabag were caught in heavy traffic -- finally got underway.

Tottenham weren't fazed by being reduced to 10 men after just eight minutes when Romania defender Dragusin was sent off for pulling down Juninho as he raced through on goal.

They took the lead in the 12th minute through Johnson's third goal in his last three games.

Qarabag conceded possession cheaply deep inside their own half and Solanke teed up Johnson for a composed finish from 10 yards.

The Wales forward had to delete his Instagram account after abuse from fans following a poor start to the season, but he has answered his critics in the perfect manner.

Sarr volleyed Tottenham's second from six yards after Qarabag keeper Mateusz Kochalski made a hash of catching a 52nd-minute corner.

Yves Bissouma's foul on Elvin Cafarguliyev gave Qarabag a penalty four minutes later, but Toral Bayramov blazed the spot-kick over.

Solanke wrapped up the win in the 68th minute, slotting home to claim his second goal since his club record move from Bournemouth in the close season.

Roma denied

Troubled Roma were held to a 1-1 draw by Athletic Bilbao after conceding a late equaliser at the Stadio Olimpico.

Roma fans were furious with the club's recent decision to sack boss Daniele De Rossi, an iconic figure during his time as a Giallorossi player, just four games into the season.

Given the unenviable task of replacing De Rossi, Ivan Juric inspired a 3-0 win against Udinese last weekend, but he was denied a second successive victory.

Artem Dovbyk put Roma in front after 32 minutes as the Ukrainian made it three goals in his last three games for his new club with a thumping header from Angelino's cross.

But Aitor Paredes headed Bilbao's equaliser after Unai Nunez nodded across goal in the 85th minute.

Jose Mourinho's Fenerbahce beat Union Saint-Gilloise 2-1 as the Portuguese boss started his bid to win the tournament for the third time in his career.

Mourinho, who won the competition with Manchester United and Porto, watched as Caglar Soyuncu put Fenerbahce ahead in the 26th minute before Christian Burgess's 82nd-minute own goal doubled the lead.

Ross Sykes' stoppage-time reply for Union came after Franjo Ivanovic missed a penalty for the visitors, who had Kevin Mac Allister sent off.

Ajax thrashed Besiktas 4-0 thanks to Mika Godts' brace and goals from Kian Fitz-Jim and Kenneth Taylor.

Olympiakos, UEFA Conference League winners last season, were beaten 2-0 at Lyon, whose second-half goals came from Rayan Cherki and Said Benrahma.

Eintracht Frankfurt blew a two-goal lead as Viktoria Plzen's Vaclav Jemelka scored the stoppage-time equaliser.

Rangers won 2-0 at Malmo, with Nedim Bajrami scoring his maiden goal for the club in the first minute before Ross McCausland struck in the 76th minute.