Darius Henderson's late equaliser rescued a replay for Millwall in their fourth-round FA Cup tie against fellow Championship side Southampton.
Liam Feeney struck the post for Millwall in the opening minutes while Harry Kane blazed over from two yards.
Henderson forced Bartosz Bialkowski into a fine save before Rickie Lambert headed home Dan Harding's cross.
But Henderson levelled the tie in the 86th-minute when he turned to fire home from Feeney's pass.
The hosts almost got off to a flying start when Feeney fired goalwards from 10 yards but his shot rattled Bialkowski's upright.
Saints failed to heed the warning and were almost undone in the ninth minute when James Henry's searching corner found Kane at the far post and he lifted his shot over from close range.
A combination of Aaron Martin's dogged defending and a smart stop from Bialkowski denied the in-form Henderson moments later as he tried to steer home a long-range effort.
Lambert, returning from a three-game suspension, then lifted a a 25-yard free-kick narrowly over the bar as the visitors started to get a foothold in the game following a slow start.
They made their increasing dominance count with a brilliantly-crafted opening goal in the 30th minute.
Ben Reeves played in Harding down the wing and his flighted cross was headed in by Lambert for his 18th of the season.
Having failed to make their promising start in the first half pay dividends, Millwall looked to get on the front foot early in the second.
Liam Trotter advanced unopposed before unleashing a powerful strike from just inside the area but Bialkowski was equal to the challenge.
Southampton had a chance to put the result beyond doubt when a swift counter-attack found Lee Holmes in space with the option to square it for Lambert but he opted to shoot and then headed wide from Lambert's follow-up.
They were made to pay when Henderson collected Feeney's pass and held off two defenders before turning to fire in the equaliser with four minutes left, making it his seventh goal in as many matches against Southampton.
Millwall manager Kenny Jackett: "Darius is on a very good run and it was a good finish from him for the goal - he put in a good performance and was a real threat for us.
"But we didn't do enough off of him, we didn't quite capitalise enough on his skills although I didn't think we deserved to get beaten.
"We had the better of the play up until their goal but then after it we were staring at a potential defeat and going out of the cup.
"The potential for us to get through is a big thing and it's a big thing financially as well. We haven't come back often enough this season and I'm pleased to say we fought back.
"The team has spirit and at times play some quality football but this game was almost indicative of our season. We had a lot of the ball but couldn't put it away."
Southampton boss Nigel Adkins: "I thought it was a real good cup tie and we look forward to the replay at our place.
"A draw was probably a good result in the end.
"There were waves of pressure coming in from Millwall but I thought Rickie Lambert scored a great goal, it was a great run and he was waiting for the space to open.
"We have missed him the last three games and there were other massive positives for us. Lee Barnard has been out for a hell of a long time and he played an hour.
"Jason Puncheon has rejoined us and worked very hard for 75 minutes before we replaced him with Luke Shaw - a 16-year-old from our youth team.
"We gave our younger players a chance and we have players who have been out injured for a long time who are close to coming back to fitness.
"We are high in the league but you always want to do well in the FA Cup."