The Mersyside club have taken seven points from the last nine available to them in the Premier League, conceding just one goal in the process.
That comes in stark contrast to Everton shipping 10 goals in their first three games of the season - including six at home to Chelsea - before being overturned 3-2 at Goodison Park by Crystal Palace.
And with a trip to the Stadium of Light to come on Sunday, Martinez believes his side are starting to click once again as they sit just two points adrift of the top six in ninth, while only three sides have scored more than their 19 goals.
He said: "In the table you are where you deserve to be. I think we're playing a lot better now than at the same stage last season in the league.
"It's quite evident now we're a more complete side. Our attacking play has been good from day one, we're looking sharp in attack.
"Defensively some of our play cost us and that shows in the table. Now we have conceded one goal in five games [including two UEFA Europa League matches against Lille], we're looking solid as a side, [and] the energy levels are strong."
Sunderland climbed out of the relegation zone with a 3-1 win at fellow strugglers Palace on Monday, thanks largely to a double from Scotland striker Steven Fletcher.
The club's first away league triumph of the season also helped to put last month's embarrassing 8-0 capitulation at Southampton to the back of their mind.
Manager Gus Poyet was full of praise for Fletcher afterwards and told the club's official website: "When you have a striker in form, you are always going to have a chance of winning football matches.
"In the air he is outstanding and he was calm to take the last goal [at Palace]."
Everton held a 19-match unbeaten record against Sunderland in all competitions until April 2013.
Stephane Sessegnon's goal gave Sunderland a 1-0 home win to end the outstanding run - which dated back to December 2001 - while both fixtures between the sides last term were won by the visiting team.
Midfielder Lee Cattermole is suspended for the hosts and Patrick van Aanholt misses out with a shoulder injury, while Jack Rodwell is a doubt with a knock.
Everton are sweating on the fitness of Gareth Barry, while Seamus Coleman's injured Achilles will be monitored ahead of the Wearside trip.
