Captain Eoin Morgan rued England's inability to cash in on a superb start, after India swooped to a straightforward five-wicket triumph in Thursday's first Twenty20 International in Pune.
Sitting pretty at 89 for one at the turn of the 10th over thanks to Hales' quickfire half-century, the visitors later slipped to 100 for four - and a final total of 157 for six.
The hard work put in by Hales, who scored 56 and shared a brisk 68-run stand for the second wicket alongside Luke Wright, was largely undone during a poor second half to the innings.
Effectively strangled by four spinners, including left-armer Yuvraj Singh, England ultimately succumbed to a one-nil deficit in the two-match series. Yuvraj was subsequently named Man of the Match after securing career-best figures of three for 19 and scoring a quickfire 38 in the pursuit.
"We got off to a great start. Alex played tremendously well along with Luke, but in that middle period we failed to kick on and score. That positivity wasn't there in our batting and we lacked about 15 or 20 runs," said Morgan, who is standing in for the injured Stuart Broad.
"We never seemed to get going again. We continually lost wickets, which is a shame because because the start we had, we were on for a good score - that was the thinking."
The tourists' showing in the field was uncharacteristically poor, with seamers Wright, Stuart Meaker, Tim Bresnan and Jade Dernbach sharing 10 wides. Debutant Meaker also dropped a reasonably easy catch at short fine-leg.
"We always thought we were in the game. We lacked a small bit of discipline in our bowling, but we were always up against it with that score on the board from Yuvraj and India," added Morgan.
The second and final T20I gets underway at the Wankhede Stadium in Mumbai on Saturday.