Later on his career, he would earn his first salary when he moved to South Africa. He transferred to South African National First Division team Mpumalanga Black Aces in January 2008 and debuted against Dynamos F.C. on 17 February 2008. He scored his first goal with the team in his debut but Black Aces lost the match 4–2. He was a member of the Black Aces team that lost against Mamelodi Sundowns in the Nedbank Cup final.

In May 2008, he joined First Division team F.C. Cape Town.

In 2009 Emenike signed a one-year loan deal with Karabükspor. Emenike made his debut in the opening game of the 1.Lig season on 23 August 2009 in a 3–3 draw against Samsunspor. He would score his first goal on 11 October, against Kartal. Emenike would score his first hat-trick of his Turkish career in a 6–1 win over Mersin İdmanyurdu and score another hat-trick on 14 February 2010 in a 4–2 win over Kayseri Erciyesspor. He went on to score 16 goals in the 1.Lig, leading the club to the title and automatic promotion.

Emenike scored on his Süper Lig debut, helping Karabükspor to a 2–1 victory over Manisaspor. On 28 November 2010, he scored his first hat-trick in Süper Lig career in a 3–0 win over Bucaspor. He subsequently scored a total of 14 goals in his debut Süper Lig season.

In May 2011, he initiated a lawsuit against the newspaper ‘Haber Turk’ for what Emenike’s agents describe as “misleading” and “malicious” claim that Emenike’s age is 7 years different than is shown on his passport.

On 25 May 2011, Emenike joined Fenerbahçe for an undisclosed fee, believed to be around 9 million euros.

On 28 July 2011, he was sold to Spartak Moscow for €10 million due to the match fixing scandal involving Fenerbahce and Emenike. Emenike had never appeared in a competitive match for Fenerbahçe.

Emenike made his debut on the opening game of the season coming on as a substitute for Ari in the 76th minute, against Anzhi Makhachkala on 14 August 2011. Emenike made his Europa League debut in a 2–2 draw against Polish side Legia Warsaw in the first leg of the qualification round. Emenike scored his first goal for the club with a 2–2 draw against CSKA Moscow. On 29 October 2011, Emenike scored his first hat-trick in a 3–0 win over Lokomotiv Moscow and the next game when Spartak played against Lokomotiv, he would score twice.

In August 2013, Emenike moved back to Turkey by returning to Fenerbahçe for a fee worth around €13m (£10.2M). He was noted to be “thrilled” and was quoted saying Fenerbahce had always been a dream for him, and he had returned to perform for the fans and win championships. His first match for Fenerbahçe against Torku Konyaspor ended in a 3–2 loss. He scored his first goal for Fenerbahçe in October 2013 against Kayserispor in the 94th minute, securing a last minute win. He scored two more against Gaziantepspor a week later, while Fenerbahçe won 3–1.

Emenike was called up to the Nigeria national football team for a friendly against Sierra Leone. He was called up to Nigeria’s 23-man squad for the Africa Cup of Nations. On 21 January 2013, he scored in Nigeria’s opening AFCON match against Burkina Faso in a 1–1 draw. He also scored the first goal in the quarter final match between Nigeria and Côte d’Ivoire which Nigeria won 2–1. On 3 February, Emenike scored a 30-yard free kick giving his country a 2–1 win over Côte d’Ivoire in the African Cup of Nations.

In 2013, he became part of the third Nigerian team to win the African Cup of Nations – Nigeria’s first continental victory since 1994. His four goals proved crucial to Nigeria’s progress through the tournament, and he was named to the team of the African Cup of Nations Team of the Tournament. However, Emenike wasn’t included in the final, due to a thigh injury. He also received the Pepsi Tournament Top Scorer, with four goals, along with Ghana’s Wakaso Mubarak.

In March 2013, Emenike was left out of the Nigerian squad for the World Cup qualifier, due to hamstring injury, which Emenike criticised Nigeria’s coach and officials of ignoring him. In June 2013, Emenike wasn’t included for Nigeria’s squad at the 2013 FIFA Confederations Cup. After four month without being called up, Emenike was called up for August’s Mandela Cup friendly match but did not participate due to injury. Emenike celebrated his absence from Eagles in Sept 2013 when he played in the 2014 world cup qualifier against Malawi – played in Calabar. He scored a goal in the two-nil win by the Super Eagles – a win which took them to the final round of world cup qualifiers. He came on as a substitute three days later in a friendly match against Burkina Faso, played in Kaduna – he scored the fourth goal in a 4–1 win for the Eagles.

On 13 October 2013, in the first-leg of last round of the World Cup qualifier against Ethiopia, he scored twice to give the Super Eagles a 2–1 lead going into the second-leg On 20 October 2015 he announced his retirement.

On 11 July 2015, Emenike signed for Al Ain on a season-long loan. On 13 January 2016, after spending six months at the club, Emenike returned to Fenerbahçe after his loan move was terminated by the club.

On 31 January 2016, Emenike signed for West Ham United on loan until the end of the season with an option to make it permanent. On 6 February, Emenike made his debut as a 73rd-minute substitute replacing Michail Antonio in a 1–0 defeat at Southampton. On 21 February, Emenike scored a brace in a 5–1 win against Blackburn Rovers in the FA Cup, his first and only goals for the club.

Emenike married former Most Beautiful Girl in Nigeria winner Iheoma Nnadi in 2016. The couple welcomed their 1st child in August 2017. They had their 2nd child on 13 March 2020.

On 6 July 2017, Emenike joined Greek champions Olympiacos for a fee of €3.8 million on a two-year deal. On 25 July 2017, Emenike made his first appearance for the club, scoring a last minute goal, helping Olympiacos to a 3–1 victory against FK Partizan, in the 1st leg of the UEFA Champions League third qualifying round. On 19 September 2017, thanks to a brace scored by Emenike at second half, Olympiacos won 2-1 Asteras Tripoli, at this 2017-18 Greek Cup clash, at Georgios Karaiskakis Stadium.

Since November 2017, the future of Emenike is up in the air, less than three weeks before the opening of the winter transfer market. According to various sources, the Olympiacos striker is under orders to train alone even though he is not recovering from any injury. In all likelihood, Emenike is set to depart the Superleague Greece champions in the January transfer window, with CSKA Moscow mentioned as a possible destination. The striker had complained of being unsafe at his home in Greece and Olympiacos were forced to hire extra security to protect him.

On 29 December 2017, Emenike has thanked Turkish giants Galatasaray for their brave step in reaching out to embattled former Arsenal and Ivorian defender, Emmanuel Eboue, who lost a bitter divorce battle, with his wife Aurelie awarded all of their assets, had to hide from cops and bailiffs after being ordered by a judge to transfer his remaining Enfield home in England to his wife.

On 17 July 2018, he mutually resolved his contract with Olympiacos.

On 27 August 2019, Emenike started to trials with Belgian 2nd division outfit K.V.C. Westerlo, for a potential contract. On 16 September 2019, he has signed with the club. Westerlo became his 10th professional club. On 14 November 2019, Westerlo released Emenike, following 5 games played for the club, due to “not bringing the level that both parties had intended” by the pertinent official club statement.