Wayne Rooney scored twice and created a goal for Juan Mata as Manchester United beat Roma 3-2 in Denver.
Rooney’s 36th-minute opener from 20 yards sparked a three-goal flurry at the end of the first half.
Mata lobbed home after a raking pass from England striker Rooney, who then scored a stoppage-time penalty.
Miralem Pjanic netted an amazing 75th-minute strike from inside his own half for Roma, before Francesco Totti’s 89th-minute spot-kick.
Victory was United’s second in succession under new manager Louis van Gaal, following a
Roma started the brighter, with Mattia Destro breaking clear in the second minute and lifting a shot over Sam Johnstone – but the ball bounced narrowly over the crossbar.
Mostly, though, it was a series of misplaced passes, poor control and general lethargy in the 30 degree heat.
Rooney lifted the torpor, curling home in exactly
at the other end of the pitch in Friday’s training session.
He then created United’s second with an arrowed pass from inside his own half. Mata’s one-touch control was instant and his delicate finish perfect
United were on a roll and when Danny Welbeck was prevented from reaching
return pass by Mehdi Benatia, Rooney’s powerful penalty sent Lukasz Skorupski the wrong way from the spot.
As promised, Van Gaal made nine changes at the break.
meant an unaccustomed right wing-back role for substitute Ashley Young – and he was soon booked for sliding into Leandro Castan.
In a game of excellent goals, Pjanic scored the most spectacular.
Spotting Ben Amos off his line, the Bosnian sent the ball sailing over the Manchester United keeper from 10 yards inside his own half.
Amos was helpless, the ball not even bouncing as it entered the net.
Totti then converted a penalty following Michael Keane’s handball a minute from time, but United held on and face Inter Milan next in Washington on 29 July.
Manchester United manager Louis van Gaal said:
“I think we didn’t play a good match. When you are 3-0 ahead, the only thing you have to do is keep the ball and the opponent has to run and run and run.
“It’s very difficult in this hot weather to do that, but we forgot. We brought Roma back into match.
“I am pleased we have won, but it was not good.”