Carlos Tevez came off the bench to make his West Ham debut, but it was Bobby Zamora who earned the Hammers a point against a lively Aston Villa.
Zamora's fifth goal of the season earned West Ham a draw
Liam Ridgewell tapped in after just four minutes to put Villa ahead when Juan Pablo Angel's header was parried.
Angel also hit the bar twice with headers as Villa had much the better of the opening period.
But Zamora deflected Paul Konchesky's header past Thomas Sorensen after the break to earn a point for the Hammers.
Tevez and his Argentine compatriot Javier Mascherano were both named among the substitutes and had their first opportunity to watch their new side from the bench.
But the opening half made uncomfortable viewing as Villa took the lead as early as the fourth minute.
Ridgewell had the easiest of tasks as he tapped in from two yards after Angel's header was parried by Roy Carroll.
But the Hammers, and Marlon Harewood in particular, failed to capitalise on a gilt-edged chance just five minutes later.
Sorensen made a horrible mess of a clearance, sending it along the ground to Harewood. But the striker scuffed his shot wide.
That was by far the Hammers' best opportunity of the opening period as Villa created all manner of problems for the home defence.
Angel powered a header against the bar on 13 minutes after slipping his marker, and another header glanced the top of the Hammers goal with Carroll beaten.
Ridgewell missed the chance to add a second as the ball hit his knee in a crowded penalty area, Gabriel Agbonlahor had a shot parried by Carroll and a Luke Moore header forced a decent save from the Hammers' keeper.
Boos rang out at half-time, but the Hammers soon restored parity.
Konchesky headed powerfully into the box from 18 yards.
Sorensen would have had it covered, but Zamora's thigh intevened and deflected the ball into the net.
West Ham twice had cause to thank their defence for not going behind again.
First, Tyrone Mears produced a wonderfully athletic overhead clearance on the line after Stilian Petrov lobbed Carroll.
And Carroll then parried Gareth Barry's shot, before Anton Ferdinand cleared Agbonlahor's follow-up which was flying dangerously across goal.
A cheer almost as loud as that which greeted Zamora's goal heralded the Hammers debut of Tevez, who joined the fray as a 61st-minute substitute for Harewood.
The striker looked lively and got the crowd behind him with a couple of surging runs, most notably one in which he cruised past Martin Laursen and sent a dangerous ball across box.
Tevez's compatriot Mascherano watched the entire game from the bench, but he did not see a dramatic finale as neither side was able to find the breakthrough.
West Ham boss Alan Pardew:
"At half-time I said 'Come on, you're the guys who have done everything to get us here.
"Let's not think that the circus is going to affect us. I think without a doubt it did in the first half.
"I know my players better than anybody. I thought we looked a bit sluggish."
Aston Villa boss Martin O'Neill:
"I thought we created some great chances - and we could have put ourselves in a strong position.
"We had enough very good chances to win the game but we were unable to do that.
"We were put under pressure at times but coped well. I thought we got tired towards the end but overall I am really pleased with the team."
West Ham: Carroll, Mears, Ferdinand, Gabbidon, Konchesky, Bowyer (Etherington 72), Mullins, Reo-Coker, Benayoun, Harewood (Tevez 61), Zamora (Cole 83).
Subs Not Used: Green, Mascherano.
Booked: Mullins, Zamora.
Goals: Zamora 52.
Aston Villa: Sorensen, Mellberg, Laursen, Ridgewell, Petrov, Davis, McCann, Barry, Agbonlahor, Angel (Baros 81), Moore.
Subs Not Used: Taylor, Whittingham, Berger, Gardner.
Booked: Barry, McCann.
Goals: Ridgewell 4.
Ref: S Bennett (Kent).