The former Celta Vigo coach singled out Espanyol's fans for special praise, stating that their support was one of the main factors behind the Cup's triumph.
"We won the game on the bus journey between the hotel and the stadium," Lotina was quoted as saying by Spanish daily Marca on Thursday.
"We saw our fans lining the streets all the way and the players got to their feet and started joining in their songs and the atmosphere was fantastic.
"You can talk as much as you like about tactics and coaching certificates but the reality of football comes down to things like that. That sort of spirit is what wins Cup finals," he added.
Espanyol won their sixth King's Cup in history after beating Real Zaragoza 4-1 on Wednesday, thanks to an early goal by skipper Raul Tamudo, Ferran Corominas's strike and a brace by striker Luis Garcia.
Brazilian striker Ewerthon scored the consolation for Zaragoza, who were favorites to win the King's Cup after eliminating Barcelona and Real Madrid on their way to final.
Lotina revealed other factors behind the current season's boost as they had a
disappointing league campaign.
"We had the luck that has deserted us in the league and that helped us beat a great team," he said.
"It was important to get the early goal and we certainly had our scoring boots on, but the difference in the scoreline does not reflect the difference between the two sides. It was much closer than that," he added.
Espanyol are just two points above the relegation zone but they secured a place in the UEFA Cup next season after their cup triumph.