Julen Lopetegui’s side have struggled for consistency at home in the PL (W3, D1, L4), but a Brighton side winless in four (D2, L2) were perhaps the ideal opponents to build some momentum against.
The Hammers began positively, with Jarrod Bowen driving a low shot at Bart Verbruggen from a tight angle, with a series of corners soon after threatening to break the deadlock for the hosts.
At the other end, Brighton rarely troubled Łukasz Fabiański in the first period, yet the veteran shot-stopper had to be alert to beat away Kaoru Mitoma's close-range shot midway through the half.
An evenly-matched contest remained level at the break, despite Bowen’s attacking endeavour, with the West Ham forward again coming close when his deflected effort trickled across the face of goal.
Shortly after the restart, the visitors were ahead when Fabiański misjudged a punch under pressure from Lewis Dunk, allowing Mats Wieffer to guide a volley into the back of the net – his first goal in English football.
With almost an hour played, things hadn’t gone to plan for Niclas Füllkrug on his first PL start, but his exit paved the way for a West Ham revival as Crysencio Summerville completed an electric front three.
Moments after that change, the now central Bowen drove towards goal before seeing his strike pushed into the path of a grateful Mohammed Kudus, who nodded home the equaliser with ease.
That goal lifted the home crowd at the London Stadium, with the contest blown wide open heading into the final half-hour.
Neither side appeared to be content to settle for a point, and with time ticking away, the Seagulls nearly retook the lead thanks to substitute Yankuba Minteh, whose square ball was bundled onto the post by Mitoma.
Fabian Hürzeler’s side had conceded five goals after the 75th minute across their last three away days, and they had Verbruggen to thank for keeping out Edson Álvarez after a scramble in the box late on.
A late barrage from the visitors ultimately came to nothing, as the two sides couldn’t be separated, meaning Brighton have now failed to win any of their last 11 PL away trips to London (D5, L6), but a hard-fought draw keeps them ninth in the table, just two points behind sixth-placed Manchester City.
As for West Ham, 14th in the standings is far from ideal, yet a congested midtable means they are only seven points from a European spot.