Everton boss Ronald Koeman has hailed his team's second-half performance in Monday's 3-0 win over Sunderland.

The Toffees were wasteful in the first period of the Premier League clash as the two teams headed down the tunnel on level terms, but a second-half hat-trick from Romelu Lukaku, who ended a 13-game scoring drought, secured all the points for the visitors.

Koeman has admitted that he was "really disappointed" with the first period, but was pleased with 'the reaction' that his team produced in the second 45 minutes.

"I was really disappointed with our first 45 minutes. It wasn't the Everton I like to see. We lost a lot of easy balls. We had difficulties but the second half is what I like to see. We got a reaction in the second half. That was the level in the second half," Koeman told Sky Sports News.

"I did not have doubts about [Lukaku]. The two goals Romelu scored with Belgium gave him a boost. It's unbelievable how good he is. I told him the best answer was on the pitch.

"I think we will be one of the teams that will fight for European football. That is a realistic target. If we play like we did in first half we will be 13th or 14th. The players are not stupid - they know what they can do."

Everton have collected 10 points from their first four Premier League games this season, which has left them in third position in the table.