Arun got the better of Stelios Halkias to script India's 2.5-1.5 win while his teammates settled for draws.
Among others, Krishnan Sasikiran was held by Vasilios Kotronias, Surya Shekhar Ganguly could not breach Ioannis Papaioannou's defence while G N Gopal survived some anxious moments before signing peace with Hristos Banikas on the top three boards.
Playing on the fourth board, Arun Prasad provided the crucial blow with a fine grind against Halkias. The fact that the win came with black pieces was all the more rewarding to the young Indian. Indians thus emerged joint leaders in the championship along with Azerbaijan, USA, Russia and Israel. The remaining teams are all sharing the second spot. It was a spectacular effort from Arun Prasad. Playing the black side of a Semi-Slav defense, the Chennai-based player was in control of the middle game when Halkias was striving for some advantage and once the queens got traded Arun was in full swing.
The players eventually arrived at a minor pieces endgame wherein Arun had an extra pawn that proved decisive. The game lasted 56 moves.
Sasikiran played out a 33-move draw with Kotronias on the top board after the former could not get advantage against the Tarrasch defence. The Indian team rested second board player GM P Harikrishna in the opening round.
Surya Shekhar Ganguly's effort against Papaioannou lasted four more moves as he played out an easy draw with black in the Queen's gambit accepted variation. Playing white, Gopal was a pawn less in the endgame against Banikas but accurate defence and some erroneous play by the Greek led to a draw after 71 moves.
In the next round, the Indians will take on the USA.
The World Team Championship is an elite team event in which 10 teams, including the top three finishers in the Chess Olympiad and the continental champions, take part.
Every team has six players with four boards to play in each round in this round robin event.