In 2005, he signed for MTK Hungária, with whom he scored 18 goals in 37 league games and helped the club to finish as runners-up in the Hungarian National Championship I in 2006–07.
"[4] Though he is mostly used as a striker, he often drops into a deeper position during games, where he is able to take advantage of the additional space to make his trademark backheel passes.
[8][9] A day later, he made his debut for the Seasiders as a 59th-minute substitute at Bloomfield Road, creating their best chance by teeing up David Fox.
Blackpool lost 3–0, and it was discovered afterwards that he had fractured his cheek bone when he clashed with a QPR defender just 60 seconds into his debut.
[10][11] Németh was one of several reserve players brought along for the pre-season friendlies, where he started the games against St Gallen, Rapid Vienna and Thailand.
[12] Due to injuries, Németh was not able to fulfil his potential at Liverpool, and subsequently moved to Olympiakos on a permanent deal following his loan spell at AEK Athens.
He assisted Ismael Blanco for the only goal of the game with a great run, and was a constant threat to the Atromitos defence throughout.
Upon returning from the FIFA U-20 World Cup, he featured in every match before the international break, most notably the 3–1 victory against Larissa on 9 November where he scored a header after being introduced as a half time substitute.
In the final game of the regular season against Asteras Tripolis, he provided both assists in a 2–0 home win, ensuring AEK went into the play-offs as the third placed team.
Throughout the season Nemeth produced more assists than goals, meaning his contribution to AEK was still important, and helped them secure second place in the play-offs.
3 days later on the 6th, Nemeth made his League debut for Olympiacos, assisting Marko Pantelić for the 4th goal within minutes of coming on in a 5–0 thrashing of Panionios.
[32] Sporting Kansas City manager, Peter Vermes said that "the fact that he was spending time in Holland before coming to us will help him adapt to our team pretty quickly".
[33] On 6 April 2015, Németh scored his first goal in the 2015 Major League Soccer season against Philadelphia Union in a 3–2 victory in the 94th minute.
[34][35] On 19 April 2015, Németh scored his first goal in an away match against LA Galaxy at the StubHub Center, in Carson, California.
[43] On 6 August 2018, Németh signed with Major League Soccer club Sporting Kansas City, who acquired him via a trade with New England Revolution.
[45] On 26 February 2020, Slovakian club FC DAC 1904 Dunajská Streda announced that they had signed Németh after his contract had expired in Kansas City.
[48] Németh was a part of the Hungary under-17 squad that reached the 2006 UEFA European Under-17 Football Championship finals in Luxembourg.
On 14 July he scored the only goal in Hungary under-19s 1–0 victory over Bulgaria under-19s in their first group game at the UEFA Under-19 European Championships at the FK Viktoria Stadion in Prague, Czech Republic.
He played in two of three group matches, scoring once against United Arab Emirates to help Hungary finish top.
With just 3 minutes left of extra time, he latched onto a through ball from Vladimir Koman and slotted coolly past the 'keeper to secure Hungary's place in the semi-finals.
[54] His tournament ended on a high however, winning a 90th-minute penalty in the third-place playoff match against Costa Rica, taking the game to extra time after Vladimir Koman converted.
[55] On 13 November 2009 in a qualification match for the 2011 UEFA European Under-21 Football Championship he scored his first U21 goal after a reverse pass from clubmate András Simon, as Hungary beat Italy 2–0.
On 10 September 2013, Németh scored his first goal wearing the national Team's shirt in a 5–1 victory over Estonia in the 2014 FIFA World Cup qualification match at the Puskás Ferenc Stadium.