Per Mertesacker: Arsenal just had to go out and beat Southampton
Arsenal 1 - Southampton 0
Per Mertesacker hailed an important response to Tuesday night's results after Arsenal's late winner against Southampton.
Alexis Sanchez's 89th-minute goal saw off the 10-man Saints - depleted by Toby Alderweireld's injury after they had used all of their substitutes - and kept Arsenal in touch with the Premier League's top four.
Manchester United, fifth-placed surprise package West Ham and under-performing Liverpool all won on Tuesday, as did leading pair Chelsea and Manchester City elsewhere on Wednesday.
And Mertesacker said: "We needed that win desperately because everyone won yesterday so we were a bit under pressure.
"We just kept going, we always believe in ourselves.
"They were unlucky, they were one man down because of an injured player, but we deserved it because we kept going."
The win was Arsenal's third in succession, following those against Borussia Dortmund and West Brom, and their German defender said: "We want to continue that run and be more consistent, especially in the Christmas period.
"We have potential, everyone knows, but we have to show it," he added.
Few chances fell at either end in an uninspiring first half that did little to alleviate the chill in north London with Saints striker Graziano Pelle guilty of one glaring miss from close range.
Southampton were livelier after the interval, attacking with greater intent than their strangely subdued opponents, whose quest to narrow the gap on the top four lacked urgency on a night of high frustration for home supporters.
The 65th-minute arrival of Olivier Giroud lifted Arsenal, although the substitution was not without controversy as Arsene Wenger's decision to sacrifice the lively Alex Oxlade-Chamberlain was met with boos.
Santi Cazorla had endured an error-prone night, but it was Oxlade-Chamberlain who made way in a performance that will only provide further ammunition to critics who believe the club is stagnating under Wenger.
Giroud was denied with three minutes to go after Southampton keeper Fraser Foster palmed his header to safety, but seconds later Sanchez plundered the winner as Saints cracked under the pressure.
Southampton manager Ronald Koeman believed Alderweireld's injury left his side struggling at the crucial moment.
"If you lose a match in the last few minutes, it's always frustrating," he said.
"After the third change, Alderweireld had a hamstring injury and then it was 11 against 10, and that made the difference.
"It's no points today but if we keep playing this way, no problem."
Goalkeeper Fraser Forster had kept Southampton on level terms with excellent saves from Danny Welbeck and substitute Olivier Giroud in the second half.
And Koeman said: "Fraser had two or three great saves in the second half, (the save from) the header of Giroud was amazing, but it was not enough."