Sam Allardyce said he would be "crying into his wine" on Saturday night after his relegation-threatened Sunderland side conceded an injury-time equaliser at Southampton.
The Black Cats appeared set to move three points clear of the drop zone courtesy of Jermain Defoe's 85th-minute opener at St Mary's.
But Virgil van Dijk strode forward to convert a Dusan Tadic cross three minutes into stoppage time, grabbing a share of the spoils for Southampton, who had Jose Fonte sent-off for bringing down Fabio Borini with 11 minutes of normal time to go.
A frustrated Allardyce said Van Dijk's goal would ruin his weekend.
"We are scoring goals, our only problem is clean sheets," he told the post-match news conference. "And it is a massive problem.
"It was going to be my first 1-0 win and I was going to be celebrating with my family on Mother's Day.
"Now, I am going to be crying into my wine, I am telling you that now.
"I won't be very happy and hope I won't take it out on the grandkids."
Sunderland now have 15 days off before their next game, the Tyne-Wear derby at St James Park against a Newcastle side they have beaten in their last six meetings.
Allardyce added: "Three points [against Southampton], having no game next week and the other results going our way, would have meant we'd go three points clear of the relegation zone for the first time since I have been here.
"If any of the bottom three had won next week they couldn't have overtaken us.
"But we have thrown that opportunity away in just a few seconds by allowing one Southampton player to turn in our box and cross.
"We had ample time to shut him down and stop him crossing but we end up with a 1-1.
"We'd produced a fantastic performance but that ultimate clean sheet eluded us yet again."