The 2-2 result sees the north Londoners progress to the semi-finals courtesy of a 6-3 aggregate scoreline, along with Atletico Madrid, Marseille and Salzburg.
Meanwhile, Atletico held on in the rain in Lisbon to win 2-1 on aggregate against Sporting, despite losing on the night to a Fredy Montero header in the first half.
Lazio, who are third in Serie A, led 4-2 from the first leg in Rome and increased their advantage when Ciro Immobile scored his eighth goal in this season's competition in the 55th minute but Salzburg equalised a minute later through Munas Dabbur.
"They were very focused and played well as they attempted to score", Elneny said following the game, which saw him provide the two assists of Arsenal's two goals.
Boston Bruins rout Maple Leafs in game 1, win 5-1
The Leafs just had their best regular season in team history, and fans are expecting them to go pretty far in these playoffs. So when he saw David Pastrnak's shot hit off the post and flutter into the air, it was tough for Kuraly to be patient.
Predators vs. Avalanche: Game 1 Prediction
The goal was being announced when Comeau got a stick on Carl Soderberg's shot from the point to give Colorado a 2-1 lead at 4:51. Try to knock the Preds off their game... get under their skin... force the Predators into taking undisciplined penalties.
Shooting: Anish becomes India's youngest-ever Gold medalist
India now has six gold medals in shooting after Jitu Rai , Manu Bhaker , Heena Sidhu , Tejaswini Sawant and Shreyasi Singh. This wizard has also won gold medals at the ISSF Junior World Cup and the ISSF Junior World Championships.
'Maybe we were a bit surprised by the intensity of the game and we were not at the races in the first half.
"It was not the plan", said the France defender. "We always believed in it, and that makes a lot of difference".
However, just as CSKA threatened again, they were stunned by a brilliant piece of play from Welbeck.
"It is our last chance to qualify for the Champions League, so we will fight until the end".
Wenger's charges had to survive a scare to reach the last-four, however.
"You could see when you have a big difference after the first game it's hard to turn up with the same urgency than if a difference is very small and that played a part in the way we played in the first half", said Wenger.