As much as people scoffed at the £12m that Sunderland paid to sign Steven Fletcher from Wolves, it is impossible to argue with his ability in front of goal. He may not be the most fashionable or glamorous player around but there are few strikers in the Premier League who are as deadly as him at the moment and his fourth goal in three games looked like earning Sunderland their first win of the season, only for Kevin Nolan's stoppage-time equaliser for West Ham to deny them.

While the home side breathed a sigh of relief after Nolan's intervention, Sunderland were left exasperated at throwing away the lead for the third game in a row. Martin O'Neill's team have not been behind once this season and the fact that they remain unbeaten with four draws in as many matches provided scant consolation. They have now not won for 12 games and the outstanding Fletcher can only do so much.

The Scot's tally only becomes more remarkable when Sunderland's cautious tactics – inexplicable considering their attacking options – are taken into account and their opener after 10 minutes could be partly attributed to West Ham's generosity, James Collins's atrocious pass out of defence giving Sebastian Larsson the opportunity to pick out Fletcher on the left side of the area with a beautifully chipped cross. Faced by Collins, Fletcher took the ball down and then lashed a left-footed volley into the far corner. Having got his hands to the ball, however, West Ham's suspect goalkeeper Jussi Jaaskelainen should have been equal to the shot.

"You get heavily punished in this division," Sam Allardyce said, sighing. "He didn't have another chance." Indeed, Fletcher had scored his fourth goal of the season with his fourth shot of the season.

"He is playing brilliantly for us," O'Neill said. "He has scored all of our goals so far. But it's also the rest of his game. He has given us a little bit of respite at times and he is proving a quality centre-forward."

It was the first goal West Ham had conceded at home and they took their time to recover from it. Allardyce's selection, favouring Matt Taylor ahead of Matt Jarvis, was curious and the reliably frustrating Carlton Cole struggled to make an impact as the focal point of the front three. Andy Carroll's return from a hamstring injury cannot come soon enough.

Gradually West Ham found their feet and were unlucky not to level before the break. First Ricardo Vaz Tê headed Taylor's cross wide, before Nolan hooked an overhead kick past the post from a Cole flick-on. Nolan then went even closer just before half-time, only to see his acrobatic volley from Vaz Tê's cross brilliantly palmed aside by Simon Mignolet.

"We were the dominant side," Allardyce said. "Sunderland had four attempts at goal. That was it. That shows the dominance of play. Our achilles heel was that our finishing wasn't good enough and that made us struggle right until the end. I have to be concerned about that."

West Ham's response in the second half was predictably Allardycian, pushing Sunderland back with a barrage of long balls. However as the home side grew increasingly desperate after Collins's header hit the bar, they left gaps for Sunderland to exploit at the back and O'Neill was disappointed with the way his players failed to make the most of a number of inviting chances on the break, not least when David Vaughan missed James McClean's cross by inches.

Their nerves heightened, Sunderland retreated even further and they were finally punished when a loose ball fell to Nolan 15 yards from goal in the 93rd minute. This time his volley into Mignolet's bottom right corner gave the keeper no chance. The identity of the scorer, a former Newcastle captain, only deepened Sunderland's irritation.