Yakubu's second-half double was enough to hand Middlesbrough all three points at the expense of Sheffield United.
Boro took the lead thanks to Mark Viduka who turned the Blades defence on the edge of the area to rifle in low.
Their lead was short-lived when Phil Jagielka fired in a penalty after Emanuel Pogatetz fouled Rob Hulse.
But second-half pressure from Boro paid off when Yakubu poked in from a yard and then added his second from the spot after he was fouled by Chris Morgan.
Both teams knew a win would take them just that little bit further away from the drop-zone.
Boro came into the match on the back of a defeat to Blackburn while the Blades, after a poor start to the season, had won four out of their last seven league matches, that included a win against Arsenal on Saturday.
But it was Gareth Southgate's men who looked like the form team for much of the match.
The front pairing of Yakubu and Viduka gave centre-backs Morgan and Claude Davis a difficult time with their physical presence and guile.
Yakubu had a couple of chances to open the scoring. His first came in the opening 10 minutes when he turned and shrugged off the challenge of Andrew Davies before firing wide, courtesy of a deflection.
He then blazed over from 12 yards after a showboating interchange between the tigerish Lee Cattermole and Viduka.
Viduka was on one of his good days and he brought the sparse Riverside home support to life when he swivelled and jinked past a couple of attempted blocks to fire in low from the edge of the area.
Just before the goal Middlesbrough had lost defender Jonathan Woodgate with a leg injury and his departure seemed to have an undesired effect on the home backline.
On the stroke of half-time, a ball was played into the Boro area by Chris Armstrong, Hulse fell to the ground under the challenge of Pogatetz and was awarded a penalty.
Jagielka, who played in goal for some of Saturday's match against Arsenal, stepped up to slot his spot-kick in the right-hand corner of Mark Schwarzer's goal.
And just before the half came to a close Morgan's bullet header was inadvertantly blocked on the line by team-mate Danny Webber, to deny United a precious lead.
Boro came out more fired-up than United after the break but their final ball was more than often disappointing.
But their frustration turned to joy midway through the half when Viduka eluded his marker on the right to fire in a goalbound shot that Yakubu tapped in in true poacher style.
And the Nigerian made sure of the points when he placed a penalty past Gerrard after Morgan fouled the striker.
"They hung in there, managed to regroup and their response was terrific.
"Mark Viduka's a class act and has made a massive difference to us since he came back into the side."
"We couldn't cope with their strength and power. On the day they were too good for us, but we will learn from it.
"It'll be down to us, not anybody else, if we're in this division next year."