Albion and Hull will contest a replay, as Leonardo Ulloa’s 30th-minute strike was cancelled out by Yannick Sagbo to delay a potential reunion with Gus Poyet in the quarter-finals.
The two sides played out a cagey opening 25 minutes, with a limited number of goal-scoring opportunities; the best of which fell to Jake Forster-Caskey, whose spectacular bicycle kick sent the ball over the bar.
Will Buckley, one of seven changes Oscar Garcia made to the starting line-up, also fed in a pass to Kazenga LuaLua, but his shot was comfortably saved by Allan McGregor.
The game suddenly sprung to life when Yannick Sagbo saw his close-range header hit the post after Ahmed Elmohamady’s cross.
But Albion took the lead thanks to Ulloa for the third consecutive home match, playing a superb one-two with Buckley and producing a delicate dink over McGregor to give Albion the lead.
Steve Bruce’s side could then have equalised just moments later, as a Curtis Davies header hit the woodwork, before Matthew Upson inadvertently diverted Sagbo’s effort into the grateful hands of Peter Brezovan.
Ulloa then had a golden opportunity to double Albion’s lead, after heading Will Buckley’s cross wide of the target from inside the box.
Solly March was introduced as a half-time substitute for Will Buckley, and within moments of coming on the talented youngster cut in from the right-hand side only to see his shot rise over the upright.
Hull looked to test the Seagulls backline with set-pieces after the break, as Tom Huddlestone’s low driven free-kick was narrowly cleared over the crossbar by Keith Andrews.
The Tigers then showed a real attacking intent by bring on both Matt Fryatt and George Boyd for Stephen Quinn and Abdoulaye Faye just past the hour mark; but neither player could make a real impact as Bruce’s side were restricted to long-range efforts.
The best of which came when Huddlestone’s ferocious free-kick was blocked before Sone Aluko’s follow-up was also stifled by the Albion wall.
The winger then linked up well with skipper Inigo Calderon, but the Spaniard’s long-range effort also cleared the crossbar.
Albion were then hit with an agonisingly blow as Sagbo levelled for the Premier League side. Aluko played a dangerous ball into box, which Sagbo controlled, took a touch past Lewis Dunk, and produced a cool finish that slipped underneath Brezovan.
The Seagulls then nearly stole the tie in the final minute of normal time, as March corner fell to Dunk inside the box only for his header to be cleared off the line.
But It could have been worse for Albion, when David Meyler’s headed an effort goalwards, only for Forster-Caskey to clear the ball off the line to ensure Albion will now travel to the KC Stadium for a replay on Monday 24th February.