The former Liverpool striker scored a second-half equaliser as his side beat the Philadelphia Union 7-6 on penalties following a 1-1 draw after extra-time to take home the 2015 title.
Sporting KC began the match at PPL Park as favourites but went a goal down in the 23rd-minute when Sebastian Le Toux – the competition’s modern scoring leader – latched onto a sublime long ball from Vincent Nogueira before firing a shot past goalkeeper Tim Melia.
Peter Vermes’ men grabbed an equaliser in the 65th-minute, however, when Nemeth, who joined SKC on a free transfer in December, finished off a well worked team move with a beautiful curling strike from the edge of the box.
It was the 26-year-old Hungarian striker’s fifth goal in only four Open Cup games and proved decisive for his side on the night, as the match would go to penalties after neither team could find a winner through 90 minutes or extra-time.
Union head coach Jim Curtin made the bold call of replacing keeper Andre Blake with shootout specialist John McCarthy in the 120th-minute but the local product could only save one of the opposition's first five attempts, which happened to be Nemeth’s.
After Maurice Edu missed Philadelphia’s third attempt, the goal hero had the chance to give his side the advantage with the following effort but saw it just tipped wide.
His miss did not matter in the end, though, as Sporting No. 1 Melia later pulled off a sudden death stop from Andrew Wenger to allow former Barcelona prospect Jordi Quintilla to step up to net the deciding spot-kick and hand the tournament’s 2012 winners another title.
For Nemeth himself, it marked another milestone in what has been a successful first season in the States so far.
With nine goals and six assists in 24 MLS appearances, the 18-times capped Hungarian has proved an inspired signing for the Western Conference outfit, having taken the scoring burden off fellow front man Dom Dwyer and won the MLS Player of the Month award for May in the process.
His form has even earned him a recall to the national team in recent months and, speaking after the win over Philadelphia, KC boss Vermes was full of praise for his impact – both in the game and since joining the club.
“Krisztian is a quality player,” Vermes told Sporting KC’s official website after the match. “In these types of games, the difference between scoring a goal and winning and losing is very marginal.
“Big players step up in those opportunities. Krisztian is a big player and a quality player.”
Nemeth could have the chance to help his team win another piece of silverware in the coming months, too, as SKC look set to secure a play-off spot for the fifth straight campaign going into their final four regular-season games.
He never managed to make a first-team appearance during his three seasons at Liverpool between 2007 and 2010 but, having been showcasing glimpses of the talent that first took him to Anfield as a teenager since arriving at Sporting Park, the 2013 MLS Cup winners will be hoping that he can guide them on another championship run.