Cani's brilliant effort from just inside Osasuna's half helped Villarreal to a 4-2 home win as La Liga reached the midway point of the season on Saturday.
It was the pick of the goals on a day when Jose Callejon's double helped fifth-placed Espanyol to a 2-1 victory at Sevilla and Athletic Bilbao beat Racing Santander 2-1 to climb to sixth.
Third-placed Villarreal's ninth home win in 10 games moved them five points clear of Valencia, who are level on 34 points with Espanyol ahead of Sunday's home game with Deportivo Coruna.
Leaders Barcelona host Malaga in Sunday's late kickoff after Real Madrid, two points behind their arch rivals in second, play at Almeria earlier in the day.
The ball rolled to Cani in a central position in the 50th minute at Villarreal's Madrigal stadium and he belted it over the head of Osasuna goalkeeper Ricardo Lopez.
Cani said he scored a similarly spectacular effort as a youth player at Real Zaragoza.
"You attempt these goals but they only rarely come off," the 29-year-old said. "I saw the keeper slightly off his line and luckily it turned out well."
The wonder strike put Villarreal back in front after Osasuna's Krisztian Vadocz had cancelled out Marco Ruben's opener.
Villarreal's Joan Capdevila and Gonzalo Rodriguez also scored either side of a Javier Calleja strike for the visitors.
In Seville, Callejon netted in each half to claim the three points for Espanyol and an Alvaro Negredo volley in added time was little more than a consolation for the home side.
Defeat spoiled the welcome return to the squad of Sevilla defender Sergio Sanchez after surgery on a heart condition and an absence of more than a year.
Bilbao were cruising at home to Racing when Javi Martinez and Iker Muniain put them two ahead after 10 minutes.
The visitors pulled a goal back through Ivan Bolado before they had forward Pedro Munitis sent off in the final minute.
In other matches, promoted Real Sociedad checked Getafe's bid for a European berth with a 4-0 away win and there were also much-needed victories for Zaragoza and Sporting Gijon.
Zaragoza won 1-0 at home to fellow strugglers Levante, their third win in 19 league matches, and Sporting saw off visiting Hercules 2-0.