Jose Mourinho admitted Tottenham needed the boost of a 2-1 north London derby win over Arsenal to offer the club’s fans a tonic after a troubled season.

A year on from reaching the Champions League final, Spurs are hoping to salvage their season just by qualifying for the Europa League as victory took them above their local rivals into eighth with three games of the Premier League season remaining.

A dire 0-0 draw at relegation-threatened Bournemouth on Thursday, in which Tottenham failed to muster a single shot on target, raised more questions over their direction under Mourinho, who replaced the sacked Mauricio Pochettino in November.

On Sunday, Spurs came from behind for a much-needed win as Son Heung-min cancelled out Alexandre Lacazette’s stunning strike before Toby Alderweireld powered home the winner nine minutes from time.

“It was not a great season for fans to enjoy so this is really important for that,” said Mourinho. “On top of that now we can still fight until the end for a Europa League position.”

Tottenham have grown accustomed to Champions League football over the past four seasons, but Mourinho – who won the Europa League while in charge of Porto and Manchester United – is desperate for the consolation prize of a place in Europe’s second-tier competition next season.

“It is not a competition I am in love with, that I like much to play, but when you can’t play the Champions League, you play Europa League. I only twice in my career played in the Europa League and won it twice. It wouldn’t be bad to play a third time and to win a third time.”

Defeat was the first in six games for Arsenal, who drop to ninth, as old defensive frailties came back to haunt Mikel Arteta’s men after an impressive spell. “I’m disappointed, frustrated and really sorry for the boys,” said Arteta.

“The way they played showed who we are. We pressed them high for them to kick the ball long and defend in a low block. But if you give the two goals away we have given against these players, it is hard to win a derby.”

There was more urgency from Spurs from the off as Lucas Moura tested Emiliano Martinez inside the first minute before the Argentine ‘keeper stood up well to deny Harry Kane’s attempted lob.

Arsenal’s impressive form in recent weeks put them in position to finish above Tottenham in the table for the first time in four years. They were on course to open up a four-point lead over Spurs when Alexandre Lacazette picked up a loose ball 25 yards from goal and blasted into the top corner.

However, Arsenal quickly undid that good work as Sead Kolasinac’s wayward pass allowed Son to outsprint David Luiz before coolly chipping the ball over the onrushing Martinez.

Both sides came close to scoring again before half-time as Ben Davies hit the bar for Tottenham and Nicolas Pepe curled just wide at the other end as the action mirrored a pulsating 2-2 draw at the Emirates earlier in the season, even if there was not the atmosphere synonymous with a derby.

With Arteta audibly orchestrating his troops from the sidelines, Arsenal controlled long spells of the second half, but failed to make their pressure count. “If we keep playing like that and eradicate the mistakes, we are going to win many games because we make it very difficult for teams to play against us,” added Arteta.

Aubameyang smashed the visitors’ best chance off the crossbar before he was denied again by Hugo Lloris flying low to his left to turn the ball behind for a corner. However, Spurs were always a threat on the counter-attack. Martinez had to be quick off his line to deny Son a tap in for his second after Kane outmuscled Shkodran Mustafi.

Kane was then denied once more by the Argentine goalkeeper from a narrow angle, but from the resulting Son corner, Alderweireld leapt highest to head into the far corner.