Arsenal's last-gasp win at Newcastle to close on Premier League leaders Liverpool will "give them huge confidence" they can win the title race, says Sky Sports' Gary Neville.
Gabriel headed in a stoppage-time winner at St James' Park on Sunday to complete a stunning turnaround victory after Mikel Merino had cancelled out Nick Woltemade's opener.
Arsenal were adamant they had been denied a penalty in the first half but showed resilience to battle back and capitalise on Liverpool's defeat at Crystal Palace on Saturday. Mikel Arteta's side now trail the defending champions by just two points.
"So big for Arsenal, so big for Arteta," said Neville on co-commentary.
Neville had been critical of Arsenal's approach in their 1-1 draw at home to Manchester City last weekend but praised the Gunners for going for glory in the North East.
"A week ago the glass was half empty, now it's more than half full," he said. "Liverpool lose, Arsenal win in stunning fashion.
"They deserve it, they were the better football team. [Arteta] made really good subs, he started with a strong team. That will give them huge confidence.
"You shouldn't have swing weekends this early. But the Liverpool players sitting at home watching this will perhaps sink slightly."
There were ecstatic celebrations among the Arsenal players when Gabriel scored and in the away section, as the team which have finished second three years in a row grabbed a statement victory.
"It's mayhem on the pitch and it's mayhem up there [in the away section]," said Neville in the moments after Gabriel's goal.
"It feels huge. We're in September. It shouldn't do. But we're talking about a team that haven't shown intent. And they've gone and done it here at St James' Park.
"Arteta - a week ago, the handbrake was on. And now the kitchen sink has been thrown at a game and it has come off for him!"