Joe Hart kept West Ham in the FA Cup after the Hammers survived a scare at his old club Shrewsbury.
The hosts, second in Sky Bet League One, dominated for long spells and fully deserved another shot at the Hammers after a 0-0 draw.
West Ham needed Shrewsbury-born Hart, who began his career with the Shropshire side, to save well from Mat Sadler and Shaun Whalley while Jon Nolan fired over late on.
The Premier League visitors, who only made four changes from their last league outing, failed to test the committed Shrews after a limp display.
But the hosts were unable to find a way through to ensure David Moyes, a former Town player, avoided another embarrassment after suffering a shock as Everton boss in 2003 when Shrewsbury beat the Toffees 2-1.
It was the last time Shrewsbury had faced a Premier League side in the FA Cup and they were hunting another upset with 31 places separating the sides.
And they held their own during a competitive start which lacked quality and gave little suggestions of the gap, and level of finance, between the clubs.
It took until the 26th minute for a serious chance, which Shrewsbury conjured, but the unmarked Ben Godfrey failed to convert Whalley's free-kick.
Omar Beckles volleyed over soon after while the Hammers failed to trouble their hosts and they needed Hart - who had to borrow a hat from a fan to deal with the low winter sun - to rescue them twice before half-time.
First skipper Sadler wriggled his way past several challenges and raced into the area only for Hart to superbly deny him and the England goalkeeper then beat away Alex Rodman's effort.
BRILLIANT: Joe Hart gets a hat thrown in for him by a West Ham fan because the sun was in his eyes. The magic of the cup...— BenchWarmers (@BeWarmers)
The slapdash Hammers had little answer as Shrewsbury grew in confidence with Javier Hernandez and Andre Ayew passengers who were too easily brushed off by the hosts' robust defence.
Moyes' side lacked invention and desire and the hosts sensed blood after the break.
They remained in the ascendancy without testing Hart and were even untroubled while down to 10 men when Sadler needed a head wound bandaged.
The Hammers offered next to nothing in attack, leaving on-loan Manchester United goalkeeper Dean Henderson under-employed for Shrewsbury.
Hart, though, did not make a meaningful save in the second half, despite Town's efforts, and West Ham were let off the hook with four minutes left.
Max Lowe robbed the dawdling Josh Cullen on the byline and crossed for Nolan but the midfielder blazed over from 10 yards.