Toss England, chose to field
New Zealand 201-4 (20 overs)
England 196-5 (20 overs)
Man of the match Hamish Rutherford (New Zealand)
Series New Zealand lead 2-match series 1-0
McCullum has been lauded for his intuitive captaincy during the Black Caps' tour of England and it proved decisive on Tuesday night as they clung on to defend 201 for four on a fast-paced Kia Oval wicket.
With England on 134 for two in the 14th over, and seemingly on track for their highest ever chase, McCullum rolled the dice and left in a slip for Morgan.
The left-hander obliged the risk by slashing a chance that Ross Taylor brilliantly held onto before Luke Wright (52) edged behind in the next over to leave England needing 63 from six overs.
Ravi Bopara still managed to take the game to the final ball but when he failed to hit Corey Anderson for six – which would have secured a super over – England were left short by the same margin they lost Sunday's Champions Trophy final to India.
"I think there were a couple of turning points," said Morgan, who was one of just four players retained from Sunday's loss and was named captain in the absence of the rested Stuart Broad.
"To stop a lot of our momentum they kept taking wickets which is very difficult. They did take a gamble by having a couple of slips in and it did pay off.
"It could have went either side of him or I could have got more on it. It is little margins to change the game. Today they weren't on our side."
Despite New Zealand posting their highest score on international soil Morgan felt confident his side could still chase it down – with a shortened southern boundary to target.
"It was probably 10 short of par, but I felt probably we could have easily chased it," he said. "If we hadn't have lost two wickets around the 14-15 over mark we could have easily chased it down.
"Coming to the back end we need guys who are established, especially with a short boundary on one side.
"It's very small margins especially in Twenty20 on a very good wicket. One blow and we would have won the game.
"There is not a great deal to be disappointed about and hopefully we can turn it around for Thursday's second game."
Kevin Pietersen will return for that match – his first for England in three months following a knee injury sustained on the tour of New Zealand.
The match will be the right-hander's only England appearance before the first Ashes Test, which starts at Trent Bridge on July 10.
Pietersen returned to action with a near run-a-ball unbeaten 177 for Surrey against Yorkshire in the LV= County Championship at the weekend and Morgan admits he would not be surprised if he immediately turned match winner for England.
"My role is to get him in and his role is to win the game," he said. "Kevin is a huge part of English cricket and has been for a long time.
"What he brings to the table probably very few people at the world can.
"He can take the game away from you at any stage and we saw during the week the way he performed he takes a lot of pride in when he goes out there and bats. He looks in good form."
McCullum was pleased with his side's performance but denied his decision to employ a slip had been a risk, but rather a necessity.
"It took a pretty special catch for it to come off," he said. "To me it wasn't a risk because if we didn't have a slip in place the game would have petered out.
"Sometimes it comes off and looks great – thankfully today it did."
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