Peter Whiteford of Scotland shot a second-round four-under par 68 in chilly, overcast conditions to take a two-stroke lead in the $2.4 million Avantha Masters on Friday.
Whiteford, who shared the first-round lead with Spaniard Alejandro Canizares, fired six birdies, three bogeys and an eagle three to move to 10-under par 134 at the half-way stage.
Thailand's Prom Meesawat was in hot pursuit of the Scot on 136 after a flawless second round of eight-under-par 64 in which he birdied five of the last six holes.
Two other Thais, Chapchai Nirat and Kiradech Aphibarnrat, Australian Kieran Pratt and Jean-Baptiste Gonnet of France were three strokes behind the leader on 137 each to set up a keen tussle over the remaining two days.
India's richest golf event, tri-sanctioned by the European and Asian Tours and the Professional Golf Tour of India, is being played at the par-72 DLF Golf and Country Club on the outskirts of New Delhi.
Two-time Major winner John Daly withdrew from the tournament due to an elbow injury sustained in the first round when he struggled to seven-over par 79 with six bogeys.
Former British Open champion Todd Hamilton failed to make the cut after ending the second day at nine-over par 153.
Whiteford, 31 and looking for his maiden European Tour title, conceded he was fortunate to stay at the top of the leaderboard.
"I had a sticky patch at the start," he said. "It was freezing cold this morning and a lot harder.
"But once it warmed up a bit, I started to play better and gave myself a few chances. I had a good eagle on the sixth which kick-started me to finish well.
"I just need to concentrate. To be 10-under is very good, but I would not say I'm overly confident. I just need a good round tomorrow to be in contention come Sunday."
Prom, looking to end a six-year title drought since his last win in South Korea in 2006, took advantage of the chill to storm up the leaderboard with eight birdies.
"Everything is going well," said Prom. "It was very cold in the first three holes but it got better when the sun came up. I like the cold better than the hot and humid weather as I tend to perspire a lot."
Sixty-seven players made the cut which was set at even-par.
Second-round leaders in the Avantha Masters at the par-72 DLF Golf and Country Club:
134 - Peter Whiteford (SCO) 66-68
136 - Prom Meesawat (THA) 72-64
137 - Jean-Baptiste Gonnet (FRA) 68-69, Chapchai Nirat (THA) 70-67, Kiradech Aphibarnrat (THA) 68-69, Kieran Pratt (AUS) 71-66
138 - Soren Hansen (DEN) 70-68, Thongchai Jaidee (THA) 68-70, Jamie Donaldson (WAL) 68-70, Gregory Havret (FRA) 68-70, Marcus Fraser (AUS) 69-69, Marcel Siem (GER) 69-69, Shamim Khan (IND) 70-68, Thorbjorn Olesen (DEN) 71-67, Anirban Lahiri (IND) 69-69