Rotherham gave their survival hopes a major boost by seeing off Nottingham Forest 2-1 at New York Stadium.
Forest's play-off hopes were dented severely by Ihiekwe's winner. They had levelled in the first half through former Miller Lewis Grabban after Michael Smith's early opener.
Both sides looked like scoring in the opening few minutes as Rotherham's Richie Towell had a fierce shot blocked by Ben Watson, with the Millers' players claiming he had used his hand.
Still smarting from that decision, Rotherham almost went behind at the other end when Yohan Benalouane's improvised back-heel bounced off the post and rolled agonisingly along the goal-line.
Rotherham made the breakthrough in the 10th minute, with Smith controlling Will Vaulks' long throw and placing his shot beyond Costel Pantilimon into the far corner.
Forest then struck the same post as earlier through Grabban, who could not get a clean connection on his volley.
Jon Taylor then tried his luck from Smith's flick-on but his powerful volley swerved over the bar.
Grabban did grab the leveller after 28 minutes, the striker latching onto a through ball and after initially being denied by Marek Rodak, he tapped the ball in at the second attempt.
Grabban had the first opportunity of the second half after he connected with Matty Cash's cross but Rodak was on hand to tip it beyond the post.
Semi Ajayi then headed wide from Vaulks' cross and Pantilimon had to tip over Taylor's cross as Rotherham pushed to retake the lead.
They did just that in the 60th minute as Ihiekwe thundered a header into the top corner after Smith had headed the ball back across goal from Joe Newell's cross.
Taylor looked to extend the lead further but his powerful effort was palmed away by Pantilimon and then cleared to safety by Molla Wague, with Rotherham players lurking for a tap-in.
Even with two players out of position at full-back, following injuries to Joe Mattock and Billy Jones, Rotherham defended resolutely in the final 10 minutes.
Forest could still have levelled after Cash capitalised on Ajayi's weak clearance and swung in a wicked cross which substitute Arvin Appiah was inches away from poking in.