Niclas Fullkrug came off the bench to net a well-placed winner as West Ham came from behind to beat Everton 2-1 in the Premier League Summer Series.
West Ham had the better of the play almost throughout against an Everton side still struggling with defensive absences, and eventually got their just reward for their possession dominance.
The impact of a full pre-season under Graham Potter was evident from kick-off in Chicago with the Hammers determined to attempt to play through their opponents and often willing to take risks with their passes.
But the risk young defender Kaelan Casey took for Everton's opener was purely one of a concentration lapse, as his square pass on the halfway line was pounced upon by Harrison Armstrong.
He raced through before freeing Idrissa Gana Gueye, whose low effort was cheaply let under his glove by Wes Foderingham.
That would not be the worst goalkeeping error of the half, as an innocuous diagonal skimmed the gloves of new Everton keeper Mark Travers as he came to punch and fell kindly for Lucas Paqueta to level.
West Ham made seven changes at the break and immediately stepped up their dominance, with Fullkrug firing home the winner with a placed finish from a tight angle 20 minutes into the second period.
Everton's summer striking arrival Thierno Barry showed brief glimpses to give hope of a potential leveller but it never materialised, with a Charly Alcaraz header the closest the Toffees came to getting their first points of the Summer Series on the board.
Analysis: It's only pre-season - but Everton are 'struggling'
Sky Sports' Ron Walker:
"Everton's pre-season campaign has been hit by defensive injury set-backs which have affected their preparations but two goals in four games, one of those against fourth-tier Accrington Stanley should be a greater concern.
"There's always a pinch of salt required in friendlies but the Toffees look limited going forward. Playing with a low block and a five-man defence against West Ham caused its own problems getting up the pitch and beyond Gueye's opener and a couple of half-chances after half-time they had little to show across the 90 minutes in Chicago.
"Moyes himself said Everton are 'struggling' to bring extra bodies in which is an added worry. Harrison Armstrong was their most dangerous threat on Wednesday night with a couple of direct runs and a nice assist for Gueye's goal. But as West Ham popped the ball around with increasing regularity, it was far harder to discern the patterns of play in the Toffees' build-up.
"It wasn't aided by a lack of individuals with the obvious quality required to take a game by the scruff of its neck. At one point last season Everton had the second-best chance conversion rate of anyone in the Premier League since Moyes' return, and that was never going to be sustainable.
"The major caveat is that with Charly Alcaraz behind Beto and a settled back four, Everton begin to look more capable. But whatever new signings do materialise, and the existing team at the Hill Dickinson Stadium, the real test will be how quickly they can get up to speed with their opening-weekend trip to Leeds, live on Monday Night Football, now 19 days away."
Moyes: We're not ready to start the season
Everton head coach David Moyes:
"It wasn't so good again. We were a little bit better in the second half than the first, and we conceded a couple of really bad goals against Bournemouth but we've done that again tonight. We can always work on it to become better.
"We made pretty poor mistakes on the ball for the goals. We're looking to make more additions and do better, if we're going to lose games we're not going to let that happen.
"We're not ready to perform well enough in this tournament. We're not ready to start the Premier League season.
"I'm not overly concerned [by the results] because I don't have the players which I need and what I want. And obviously, we're up against it right from the start. We knew before we came [to the US] we were going to be really up against it. So, it was never going to be us coming here and winning [games].
"I think our attacking play at the moment has been really poor. I think we haven't created enough chances.
"I think the way we're playing in that area of the pitch at the moment has been really below par. But we've made individual mistakes which has shown us up for that as well.
"It stood out tonight, some goalkeeping mistakes. At the weekend, we made a couple of mistakes against Bournemouth."
Potter pleased by Hammers' resilience
West Ham head coach Graham Potter:
"It's pleasing. I don't think we came back from a goal down last season, it's not a habit you want to get into but it's a good characteristic to have.
"The intensity was there from our perspective. Fullkrug can play a great role. His intensity off the bench is something unique but it's nice to have the option with him from the start.
"He brought energy to the team and near enough made the goal for himself."
Saturday July 26 - MetLife Stadium, New Jersey
Everton 0-3 Bournemouth
Man Utd 2-1 West Ham
Wednesday July 30 - Soldier Field, Chicago
West Ham 2-1 Everton
Thursday July 31 - Soldier Field, Chicago
Manchester United 4-1 Bournemouth
Sunday August 3 - Mercedes-Benz Stadium, Atlanta
Bournemouth vs West Ham - 7pm kick-off, live on Sky Sports
Manchester United vs Everton - 10pm kick-off, live on Sky Sports
