Ipswich came from two goals down to earn a draw at Upton Park in the first leg of their play-off tie.
Shefqi Kuqi equalised from close range after a mix-up between keeper Jimmy Walker and defender Anton Ferdinand.
Marlon Harewood had put West Ham ahead from five yards before Bobby Zamora's strike doubled the lead.
Ipswich pulled one back when Tommy Miller's free-kick went in off goalkeeper Walker after hitting the wall and the base of the post.
West Ham dominated large periods of the game and Ipswich will be relieved to go into the second leg at Portman Road on level terms.
Ipswich boss Joe Royle lasted just 18 minutes in the stand before making his way to the touchline to try and curb West Ham's early dominance.
Alan Pardew's team were first to every ball and played like a team for whom there was no such thing as a lost cause as they threatened to take the tie away from Ipswich.
The Hammers' opener had come after seven minutes, Zamora's flick-on setting Matthew Etherington free down the left before crossing for Harewood to score.
Ipswich were furious not to be awarded a foul in the build-up when Harewood appeared to tangle with his marker Richard Naylor as he made his way into the penalty area.
But if West Ham were in any way fortunate with their opener there was no doubt about the second.
Etherington again cut down the left, comfortably outpacing Drissa Diallo, before his low cross broke to Zamora for the striker to slot home his 99th career goal.
Davis saved from Harewood while Jason de Vos handled on the edge of the Ipswich area but the infringement went unnoticed by referee Uriah Rennie.
More crisp interplay from the Hammers - with Etherington at the centre of everything - gifted an opening to Zamora, but he scuffed his shot.
On the stroke of half-time, however, Ipswich scored a fortuitous goal.
Tomas Repka was harshly booked for a challenge on Kuqi and from the subsequent free-kick the ball eventually went in off the leg of goalkeeper Walker.
The match was stressful for Pardew
Town, with Darren Currie and Matt Richard replacing the ineffective Diallo and Kevin Horlock at the break, enjoyed a lot more possession at the start of the second-half.
And Kuqi should have scored from a corner but made poor contact with his header.
But West Ham continued to threaten and Etherington went close with a free-kick, while Ferdinand was denied by an unbelievable one-handed save from Davis.
The importance of Davis' crucial save was put in stark perspective when Hammers keeper Walker and Ferdinand both went for the same ball with 14 minutes left.
The ball dropped obligingly at the feet of Kuqi, who equalised from short range.
West Ham: Walker, Repka, Ferdinand, Ward, Powell, Reo-Coker, Newton (Rebrov 86), Mullins, Etherington, Zamora (Noble 76), Harewood.
Subs Not Used: Bywater, Fletcher, Dailly.
Booked: Repka, Etherington.
Goals: Harewood 7, Zamora 13.
Ipswich: Davis, Wilnis, De Vos, Diallo (Currie 45), Naylor, Magilton, Miller, Horlock (Richards 45), Westlake, Bent, Kuqi.
Subs Not Used: Price, Counago, Bowditch.
Booked: Wilnis, Naylor.
Goals: Walker 45 og, Kuqi 74.
Ref: U Rennie (S Yorkshire).