Montenegro have 10 points from four matches, two more points than England from the same number of games with the two teams yet to play each other on the road to the 2014 finals in Brazil.
Poland are third with five points from three games, followed by Moldova on four from as many matches, Ukraine on two points from two games and San Marino with zero from four.
Coach Branko Brnovic rested several first-choice players against San Marino, including Fiorentina striker Stevan Jovetic, and his replacement Delibasic snatched his chance even if it was against one of the most timid rivals he is ever likely to face.
San Marino, who are yet to score a goal in this qualifying campaign, were on the back foot from the start and only a pair of reflex saves from their goalkeeper Aldo Simoncini denied Delibasic and his strike partner Fatos Beqiraj from giving the home side an early lead.
But Simoncini was helpless in the 14th minute when Delibasic tapped in a perfect low cross by Aleksandar Volkov after the left back's one-two with forward Filip Kasalica carved open the visitors' defence.
Delibasic made it 2-0 in the 31st minute from point blank range after Mitar Novakovic headed a teasing Simon Vukcevic corner into his path.
Defensive midfielder Zverotic added the third midway through the second half, burying a low shot with the tip of his boot from 15 metres, while substitute Blazo Igumanovic rattled the woodwork with a stinging free-kick in the closing stages.
Main striker Mirko Vucinic was suspended.
- Sports & Recreation
- San Marino