Swansea City remain top of the Championship despite slipping to defeat at the hands of fellow promotion contenders West Ham United.

Divine Mukasa's first-half strike was enough to seal victory for the hosts, and condemn the Swans to their first league defeat at the Swansea.com Stadium.

Ben Cabango came closest to finding a leveller, slamming an effort against the crossbar, but Lawrence Vigouroux was certainly the busier of the two goalkeepers and made a series of impressive saves to keep his side in it.

Swansea remain a point clear of the Hammers, who move up into second, with Middlesbrough's draw with Cardiff City ensuring they would stay at the summit regardless of this result.

Vitor Matos made four changes from the side that beat Millwall in midweek, with Ronald starting at right in light of Filip Lissah's suspension.

Swansea came into this game with the best defence in the league, while West Ham had the Championship's most prolific attack.

Perhaps it subsequently shouldn't have been too much of a surprise to see chances hard to come by at both ends in a frantic opening half an hour, with both goalkeepers enjoying a relatively trouble-free start to a highly-anticipated affair in SA1.

But that all changed on 34 minutes, as Marko Stamenic was caught in possession by Pablo, who then sent an inch-perfect pass through for Mohamadou Kante, and his low ball was comfortably swept home by Mukasa.

A disappointing goal to concede, but it appeared to stir the hosts.

Ronald whistled an effort just wide from 25 yards a few minutes later, while Cabango was denied by the woodwork just before the break.

Josh Tymon's freekick was headed back across goal by Moussa Yeo, and the Swans skipper rattled the underside of the bar before watching it bounce clear and into a goalmouth scramble that eventually ended with Mads Hermansen smothering.

It nearly got worse for Swansea just after the break, with Jarrod Bowen taking advantage of Stamenic's poor pass to Fulton to dart into the area and shoot, only for Vigouroux to palm away.

The Chilean then made two more big saves, getting down to deny Pablo and then Bowen again, with West Ham looking to put the game to bed.

At the other end, Adam Idah sent a low shot narrowly wide after being set up on the edge of the area by substitute Stephen Eustaquio.

Cabango missed another good chance four minutes later, snapping at a shot from close range after getting on the end of Josh Tymon's low cross.

Tymon then arched a ball for Idah moments later, but the Irish striker couldn't keep his header down.

Vigouroux made another huge stop to deny Castellanos as the game ticked towards the final 15 minutes, before Ronald saw a speculative effort deflect off Widell and wide.

Morato and former Swans hero Joel Piroe both sent efforts wide at the other end late on, while Ronald fluffed his lines deep into stoppage-time, sending a tame header across goal at the far post.

Staying top of the league will be some comfort to the Jack Army, who will hope their side can bounce back at Queens Park Rangers next weekend.

Swansea City: Vigouroux; Ronald, Cabango, Welsh, Tymon; Stamenic (Vipotnik 76), Fulton (Eustaquio 56), Franco (Widell 76); Yeo (Just 76), Idah, Opoku (Eom 56)

Subs: Fisher, Seelt, Woodward, Heywood

West Ham: Hermanse; Veltman, Mavropanos, Kilman, Morato; Kante (Austbo 69), Engels; Bowen, Mukasa (Piroe 84), Solomon (Soucek 84); Pablo (Castellanos 61)

Subs: Areola, Walker-Peters, Scarles, Golambeckis, Orford