"Sky Sport Italia" voted the goal second place for Goal of the Season behind Paul Pogba's strike for Juventus against Napoli. After scoring 19 goals in 40 Serie B appearances for the "rossoverde," he finished the fifth top scorer in Serie B for the 2013–14 season helping Ternana avoid relegation with a 16th-placed finish. His contract was redeemed by the Umbrian club upon the conclusion of the co-ownership agreement on 20 June 2014, for an undisclosed fee. On 19 August 2014, it was reported that Leeds United had agreed a deal with the Ternana first-team captain to join the club. It was confirmed on 20 August 2014 via the player's own Twitter account that he had joined Leeds. On Saturday 23 August, Antenucci made his Leeds debut against Watford in a 4–1 defeat. Antenucci made his home debut at Elland Road on 30 August against Bolton Wanderers. On 16 September 2014, he scored his first league goal for Leeds against Bournemouth in a 3–1 win. Antenucci finished the 2014–15 season as top scorer for Leeds with 10 league goals. On 2 July 2015, Antenucci's agent Silvio Pagliari revealed that Antenucci and Giuseppe Bellusci would be staying at Leeds and that owner Massimo Cellino said both players were going to be important players for the 2015–16 season. On 31 July 2015, Antenucci was given his favoured squad number 7 for the upcoming 2015–16 season. On 8 August 2015, on the opening day of the Championship season, Antenucci started the game on the bench against Burnley but came on a substitute and scored a stunning left footed strike to put Leeds 1–0 up in a match that finished as a 1–1 draw. On 12 August 2015, Antenucci scored a penalty in a penalty shootout against Doncaster Rovers in the League Cup, with Leeds losing 4–2 on penalties after a 1–1 draw. On 19 April, Antenucci was nominated for the Leeds United player of the year award, alongside Charlie Taylor, Liam Bridcutt, Gaetano Berardi and Lewis Cook. The award was won by Taylor on 30 April. Antenucci finished the 2015–16 season as Leeds' second top goal scorer with 9 goals behind Chris Wood who scored 13. On 7 May 2016, Antenucci revealed in a post on his official Instagram account that he would be leaving Leeds. On 30 June 2016, Antenucci joined Serie B side S.P.A.L. on a free transfer from Leeds.