There was plenty in West Ham’s first 45 minutes to encourage Graham Potter: controlled spells of possession, Jarrod Bowen knitting attacks together, and a defensive line largely untroubled by clear chances. But Premier League games hinge on penalty-area moments, and Sunderland seized them. Two second-half headers — first from Eliezer Mayenda, then Dan Ballard — flipped a balanced contest, before Wilson Isidor’s late curler made the scoreline look harsher than the pattern of play.

For long stretches the Hammers looked composed. New goalkeeper Mads Hermansen made an important stop from Habib Diarra early on, the midfield recycled the ball calmly, and El Hadji Malick Diouf came closest, denied only by Ballard’s superb sliding clearance with Robin Roefs beaten. Yet when the game asked for conviction in either box, Sunderland answered with precision while West Ham hesitated — a 3–0 defeat built from a handful of decisive actions rather than 90 minutes of dominance.

A promising shape without the punch to match

Potter’s side started with control. By circulating possession through midfield and pulling Sunderland’s block from side to side, West Ham found the half-spaces for Bowen to receive, turn and connect. The movement worked: wide rotations drew full-backs out, central runners probed the channels, and when the ball broke kindly, Diouf pounced — only for Ballard’s last-ditch intervention to keep it level. It was the kind of first-half platform you want away from home on opening day.

What was missing was the finish. Eleven shots yielded modest chance quality, and too often the final action seemed a tempo off — an extra touch at the edge of the area, a cross without a target, or a shot taken with bodies still arriving. Sunderland, meanwhile, looked most dangerous in direct transition, with Diarra’s surges and Mayenda’s pin-and-spin runs hinting at the threat to come if West Ham’s rest defense lost a duel or misread a cue.

Where the game turned: two crosses, two headers

The hinge came just after the hour. Omar Alderete, on for the injured Jenson Seelt, was afforded the time to shape a tempting cross; Mayenda backed into his marker, generated the angle and glanced beyond Hermansen. It was clever centre-forward play but also a preventable concession — a delivery not sufficiently pressured and a header contested too passively.

Twelve minutes later West Ham were punished again. Simon Adingra’s deep, hanging cross found Ballard arriving untracked at the far post to guide a firm header into the corner. Both goals shared the same theme: Sunderland attacked the ball with intent; West Ham didn’t match the aggression. For a side that otherwise managed phases well, those two sequences defined the afternoon.

Hermansen’s debut and the realities of bedding in a back line

Hermansen’s first league outing for West Ham had bright notes. He stood tall against Diarra early, handled cleanly, and looked comfortable receiving under pressure to restart possession. The late third — Isidor driving and curling inside the far post — nicked his gloves but had been set up by a retreating, unprotected back line. It read more as a team concession than a goalkeeping error.

The bigger issue sat in front of him. Box defending and aerial responsibility were a beat off: Sunderland’s wide deliveries arrived without enough heat on the crosser and the first contact wasn’t owned. Those are problems of timing, communication and profile — fixable with reps, clarity in matchups, and, if needed, a tweak in personnel or marking assignments on deep crosses.

Potter’s changes, Wilson’s menace, and the search for edge

Potter turned to Callum Wilson to add penalty-area edge. The former Newcastle forward immediately occupied centre-backs more aggressively, and West Ham’s build grew more direct. The best chance of a lifeline came late when a deflected Wilson header from a set piece forced Roefs into an outstanding tip over — a reminder that with sharper service and earlier entries, the Hammers do have a finisher to attack the first post and the six-yard line.

The broader attacking pattern needs one of two shifts: either quicker vertical passes into Bowen and Wilson before the block sets, or wider, earlier crosses with runners arriving in lanes rather than flat across the line. On opening day, West Ham too often asked the final ball to beat both a set defense and the clock; the margins are thinner than that in this league.

What to take forward: clear fixes, real foundations

There’s no need for alarm. The possession framework worked for long spells, Bowen remains this team’s connective tissue, and Hermansen showed tools that will become more visible as the back four settles. The tape will be honest about the rest: defend the crosser with more intensity, assign and win first contacts in the box, and be braver about committing bodies through the middle when the ball goes wide.

Chelsea at the London Stadium will stress-test those corrections immediately, with Nottingham Forest and Tottenham to follow. But the solutions are specific and within reach: sharpen the duels in your own area, speed up the first two passes after regains, and lean into Wilson’s penalty-spot gravity. Opening day at a raucous ground punished hesitation; the next three weeks are a chance to turn a tidy platform into points.