Everton ran out deserved winners at Goodison Park, having carved out a host of chances against a Gunners team who had won five and drawn one of their previous six top-flight matches.
The Toffees delivered an authoritative performance against Unai Emery’s side, blending attacking verve and purpose with defensive resilience.
The scale of Everton’s superiority is highlighted by the fact they fired in 23 shots and restricted the visitors to just seven efforts on goal.
Sigurdsson, who joined Everton from a Club-record fee in the summer of 2017, says confidence is soaring within the squad.
“We’ve been really positive going forward and are defending really well as a team,” said the Icelander, who with 12 goals is the Blues’ joint-top Premier League scorer this season alongside Richarlison.
“When you win three games in a row, that gives the whole place a big lift.
“I think it’s the best we’ve played [since I’ve been here].
“There’s a lot of confidence in the team. We’re scoring goals and keeping clean sheets, and that gives us the platform to create things up front.”
Indeed, the result represented the Blues’ third shutout in a row against top-six opposition at Goodison Park.
Everton have yielded seven points from these contests, having drawn 0-0 with Liverpool at the Grand Old Lady on 3 March before dispatching Chelsea 2-0 a fortnight later.
Sigurdsson was eager to praise the influence of the Goodison crowd in driving the players on.
Sunday’s success saw the Toffees move to within a point of seventh-placed Leicester City.
“It’s been really good at Goodison, especially the last couple of months,” Sigurdsson added to evertontv.
“The derby was a special game – the atmosphere was incredible. It has been fantastic in the games against Arsenal and Chelsea, too.”
Phil Jagielka proved the matchwinner on Sunday, the skipper’s instinctive 10th-minute finish securing victory for Everton.
The 36-year-old centre-back was named in the starting line-up with minutes to kick-off after Michael Keane was forced to pull out through illness.
As well as netting the winner, Jagielka produced an accomplished defensive display as the Blues’ kept a gifted Arsenal attack at bay.
Sigurdsson says Jagielka’s impressive performance underlines the defender’s professionalism and the depth of the Everton squad.
“He’s come in and done fantastic,” said the Iceland captain.
“He also came into the team against Cardiff where we kept a clean sheet and won the game.
“It’s fantastic to have someone like that in the squad and it shows how good the squad is.”