Boos rang out at the Emirates Stadium after Arsenal incredibly squandered a 3-0 lead over Anderlecht and an early place in the last 16 of the Champions League. Whereas two weeks ago it was Arsenal that came up with the late goals to get a 2-1 win in Brussels, this time it was the inexperienced Belgian visitors who produced a far more implausible fight back to claim a share of the points and keep their own hopes of advancing through the group phase live.

Arsenal appeared to be cruising into the last 16 for the 15th straight season when a penalty from Mikel Arteta and strikes from Alexis Sanchez and Alex Oxlade-Chamberlain put them 3-0 to the good before the hour mark. But Anthony Vanden Borre quickly pulled one back for the visitors despite being in a clear offside position, and with 17 minutes remaining the Belgium international had his and his team’s second when converting from the spot after a hapless foul by Nacho Monreal. By that point the momentum had dramatically and inexplicably swung toward the Belgian champions. Arsenal were visibly rattled and in the 90th minute Aleksandar Mitrovic headed past Wojciech Szczesny to complete a comeback for the ages.

With a five point lead over Anderlecht and six point advantage over Galatasaray, unless further catastrophe is forthcoming, Tuesday’s result is unlikely to be critical to Arsenal’s hopes of Champions League progress. But once again carelessness looks set to cost Arsenal the chance to finish top of their group and secure a last-16 meeting with a group runner-up, rather than winner. Wins over Borussia Dortmund, at home in three weeks’ time, and away to Galatasaray, along with two defeats for Dortmund will be required to overhaul the five-point lead for the German side, unless Arsenal win by three-clear goals when the two sides meet. Frankly either scenario is currently farfetched.

If they are to defeat a Dortmund side that turned them over far more comfortably than even a 2-0 scoreline suggested in Germany, then the brittleness displayed late on must surely be eradicated. Given the particular struggles of Monreal as a makeshift center-back, manager Arsene Wenger will be desperately hoping that Laurent Koscielny is fit to line up as soon as possible.

Arsenal could even have been behind early on. United States international Sacha Kljestan cleverly skipped past the challenge of Kieran Gibbs on the edge of the box to get clean through on goal, but saw his attempted dink denied by the outrushing Wojciech Szczesny who did superbly to spread himself high and wide. Missed opportunities had cost Anderlecht dear after going in front in Belgium two weeks ago and once again Arsenal quickly seized upon their opponents’ profligacy.

While Arsenal remain far from convincing, they can continue to rely on a world-class performer operating at the top of his game. After four goals in two games and so much more besides in recent weeks, Sanchez was again by some distance the best player on the pitch and had a hand in all three Arsenal goals.

He was just getting warmed up when he lashed a shot against the outside of a post from a tight angle in the 21st minute. Three minutes later the in-form forward supplied a delightful reverse pass through to Welbeck, who was prevented from getting on the end of it by a clumsy challenge from Chancel Mbemba. Arteta took the responsibility from 12 yards and chipped it down the middle as goalkeeper Silvio Proto dived unknowingly out of its path.

Four minutes later Sanchez had his 10th goal in an Arsenal shirt. While his free-kick was struck into the wall, he took full advantage of it bouncing back to him by smashing a low volley past a slow to get down Proto at the near post. Brilliantly talented with the ball at his feet, in the second half Sanchez provided a perfect example of the intense work rate that has also set him apart from his teammates. The 25-year-old relentlessly harried Kljestan into conceding possession in his own half and from there Oxlade-Chamberlain took over and sped into the penalty area before finishing clinically.

No one would have believed at that stage that an Anderlecht team that had not made it out of the first group phase in 14 years and went into the game considerably weakened by injuries. But within three minutes of falling 3-0 behind Vanden Borre, who had been poorly beaten for Arsenal’s third goal, turned in Andy Kawaya’s cross as the assistant referee’s flag errantly remained down.

A team of Arsenal’s ambitions should have been able to brush off the concession of a single goal, instead it had a debilitating impact. Monreal could have no complaints when the referee awarded a penalty after he tried to atone for getting caught the wrong side of Mitrovic by blatantly hauling him down. After Vanden Borre sent Szczesny the wrong way from the spot, Mitrovic’s impressive impact after coming off the bench was to continue in spectacular fashion. As the clock ticked toward the 90 minute mark, the Serbian striker got ahead of Per Mertesacker in the box to head Andy Najar’s pinpoint cross inside the near post to leave Arsenal fans voicing their frustration in considerable numbers.

All Goals - Arsenal 3-3 Anderlecht - 04-11-2014 by Super-By