Craig Dawson headed in Aaron Cresswell’s free kick to give the Hammers a 32nd-minute lead at the London Stadium.
But Willock’s well-taken leveller, which came after Declan Rice had failed to nod Ryan Fraser’s cross away, earned Eddie Howe’s men a vital point and extended their unbeaten run to six Premier League games.
That equaliser was a fitting reward for former Arsenal man Willock, whose all-action display merited what was his first strike since joining the club permanently last summer.
A rapid start almost heralded a quickfire opener for Howe’s side. Fabian Schär’s long free kick into the box eluded the hosts’ backline and Joelinton nipped in front of Rice to force the chance, but Lukasz Fabianski turned his close-range effort behind.
From the resulting corner, Joelinton’s knock-down found Jacob Murphy – in for the injured Allan Saint-Maximin – and he saw his shot charged down, with Willock’s stabbed effort deflected just over.
It was a strong start from the Magpies, who were searching for a fourth league win in succession, and they continued to push the fourth-placed Hammers, who again had to be alert as Fraser volleyed Matt Targett’s cross goalwards. On that occasion, though, the Scot saw his strike inadvertently blocked by Chris Wood.
David Moyes’ men are chasing a European spot and as the half went on they began to show flashes of their quality. On-loan full back Targett, restored to the line-up alongside Emil Krafth in the absence of sidelined duo Javier Manquillo and Kieran Trippier, did well to get in the way of a low Antonio shot but on 20 minutes, the Hammers went even closer. Ryan Fredericks nodded Rice’s crossfield ball into Jarrod Bowen’s path but he was denied from a tight angle by Martin Dúbravka, who touched his goalbound attempt onto the crossbar.
The first goal of the contest came just after the half hour, when Krafth brought down Antonio on the left. Cresswell swung the free kick into a dangerous area and centre back Dawson met in, planting his header into the turf and beyond Dúbravka and into the bottom left-hand corner.
Bowen threatened a second soon after but he was made to pay for not making more of his tame effort on the stroke of half time when Willock’s opportunism sent United in level. Murphy and Fraser combined effectively down the left flank and the latter’s cross caused a problem for Rice, who couldn’t nod it clear. Willock was quick to pounce on the mistake, throwing out his right foot and flicking the ball across Fabianski and over the line, despite the Polish stopper’s best efforts.
The equaliser sparked a bit of a reaction from the hosts, who began the second half on the front foot, with Dawson seeing a well-struck half volley blocked by the impressive Dan Burn before Bowen found the towering defender in similarly uncompromising form, as the former Brighton man prevented him from turning and firing towards goal in the six yard box.
By the hour it had become a cagier contest, with both sides probing on the break. Willock was enjoying one of his best games of the campaign, finding pockets of space behind the Hammers’s midfield and driving Newcastle forward, and it was a sign of his burgeoning confidence that he opted to shoot from 30 yards after sidestepping Pablo Fornals. He couldn’t quite find the right angle, though, and curled it wide of the target.
The attacking intent from both sides remained clear to the end, with Willock and Joelinton continuing to break at speed for United and Antonio – the Hammers’ focal point up front – applying some pressure too, with a speculative strike which sailed over the best he could muster as the game drifted towards an even outcome.
