Middlesbrough remain in contention to reach two cup finals after drawing with Charlton in the FA Cup quarter-final.
Middlesbrough and Charlton will replay on 12 April
Charlton were unable to find a way past Mark Schwarzer, who made two important saves during the first half.
He dived to save Hermann Hreidarsson's free-kick and then reacted quickly to tip away a volley from the defender.
Boro might have taken an early lead but Yakubu headed over, while after the break Lee Cattermole and James Morrison might have done better with shots.
The draw means both Charlton and Boro, who replay on 12 April, will go into the hat for Friday's FA Cup semi-final draw.
Schwarzer was in superb form last week in helping Boro through to the Uefa Cup quarter-finals at the expense of Roma and the Boro goalkeeper had another impressive game.
Gareth Southgate, George Boateng and Stewart Downing also played well for Boro.
Downing put in some dangerous crosses as he seeks to win a late place in Sven-Goran Eriksson's squad for the World Cup finals.
If Middlesbrough had to soak up plenty of pressure, it was the visitors who settled more quickly to the game's tempo.
In the third minute when Franck Queudrue sent over a cross from the left, Yakubu managed to get in between Hreidarsson and Chris Perry, only to head well over.
Charlton might have been slow to start, but after Matt Holland went close with a volley, the home side began to gather a head of steam.
Hreidarsson twice drew saves from Schwarzer, first from a free-kick and then from the Icelandic defender's volley after Bryan Hughes arrowed over a cross from the right.
Schwarzer received plenty of help from his team-mates, with Gareth Southgate, Gaizka Mendieta and Queudrue making important interventions, each time depriving Shaun Bartlett of a sight of goal.
Late in the game Ugo Ehiogu, who suffered a head wound during the game, made an important block to stop a Jerome Thomas shot.
Schwarzer had a painful end to the opening half, jarring his knee in coming for a cross.
As Schwarzer hobbled back to his goal, Charlton hooked the ball into the box, but Darren Bent shot well over.
On 70 minutes Schwarzer showed excellent judgment to rush and clear the ball after Thomas' pass had sent Bent free.
Soon afterwards Charlton substitute Dennis Rommedahl went close with a curling shot after he had drifted in from the right wing.
Cattermole should have done better as the Charlton defence backed off, while Morrison scuffed his shot from a good position in the closing stages.
Charlton manager Alan Curbishley:
"We're delighted to be still in the hat - not many of us have been in a semi-final draw before.
"We've got a decent record at The Riverside and earlier this season we did very well up there in the league.
"We had chances in the first-half but didn't take them - in the end we both went for it, but no-one could score."
Middlesbrough manager Steve McClaren:
"Ugo Ehiogu and Gareth Southgate provided the platform for us.
"Charlton hit us with everything and the two centre halves as well as Mark Schwarzer and goalkeeper saved us.
"They showed their experience. We had chances in the second half, but a draw was probably a fair result."
Charlton: Myhre, Young, Perry, Hreidarsson, Powell, Kishishev (Rommedahl 62), Holland, Hughes, Thomas, Darren Bent, Bartlett (Bothroyd 76).
Subs Not Used: Andersen, Euell, Spector.
Middlesbrough: Schwarzer, Parnaby, Ehiogu, Southgate, Queudrue, Cattermole, Boateng, Mendieta (Morrison 64), Downing, Hasselbaink, Yakubu (Viduka 68).
Subs Not Used: Jones, Rochemback, Pogatetz.
Ref: M Dean (Wirral).