The club's record £8million pound buy earned a reputation as a matchwinning substitute in European games last season as Middlesbrough reached the UEFA Cup final.
Once again Maccarone came up trumps as Middlesbrough bounced back from successive defeat at Manchester City and Watford to earn valuable points.
Maccarone had only been on the field for six minutes after his second half introduction, when he grabbed the spotlight.
After going round the goalkeeper Robert Green he shot into the net from an acute angle for a fine goal.
West Ham manager Alan Pardew will have been disappointed over the result after two successive wins.
The Hammers played some slick football, but lacked finish and failed to trouble Australian goalkeeper Mark Schwarzer in 90 minutes.
Middlesbrough were in desperate need of a win to ease fears of being sucked into the relegation battle. Manager Gareth Southgate decided on a four-five-one formation with Yakubu the lone striker.
It was not an ambitious line-up for the home team, but Southgate no doubt wanted to stifle West Ham after their improved run.
Following a left-wing cross by Andrew Taylor, Fabio Rochemback fired a volley wide for Middlesbrough from the edge of the penalty area after five minutes.
The West Ham striker Marlon Harewood fired wide in reply for the visitors.
West Ham's James Collins was booked after 16 minutes for pulling back Yakubu as the Nigeria international broke through.
Middlesbrough's most dangerous attack, surprisingly, came from a long clearance by goal keeper Schwarzer that covered the length of the field.
Yakubu raced into the penalty area with only Green to beat but the goalkeeper got to the ball first.
West Ham supporters were in fine voice at one end of the ground but the game lacked atmosphere in the first half. Thrillers were in short supply even though the visitors were showing speed and precision in their passing.
Middlesbrough midfield player Stewart Downing, who has been called up by England for the friendly against Holland this week, was responsible for the best goalscoring attempt of the first half.
Downing unleashed fierce shot after 30 minutes from just inside the penalty area, but bought a fine save from Green.
Middlesbrough again threatened with a long Schwarzer clearance, but Danny Gabbidon denied Ayegbeni on the stroke of half-time with a brilliant tackle.
The fans were no doubt hoping for a better standard of entertainment in the second half.
Jonathon Spector was booked for a foul when he brought down Downing.
Harewood fired a first time shot over the bar for West Ham before he was pulled off in the 63rd minute. Substitute Carlos Tevez took over from the striker.
Middlesbrough sent on substitute Maccarone for Rochemback and it proved an inspired move by manager Gareth Southgate.
Maccarone boosted Boro with a fine individual goal. The home team began to play with much more confidence and introduced their best spell of the game in the closing stages.
Middlesbrough pulled off Downing in the 90th minute and sent on Germany international Robert Huth to bolster the defence.
The former Chelsea defender was hardly needed because West Ham failed to produce the finishing power to save the game.