Atalanta head coach Gian Piero Gasperini laughed off claims Cristiano Ronaldo has been culpable for Manchester United's inconsistent form and offered the Portuguese star praise after his last-gasp equaliser.

Ronaldo volleyed home a 91st-minute equaliser to deny Atalanta three points in their dramatic 2-2 draw in the Champions League on Tuesday.

The five-time Ballon d'Or winner levelled the game twice late in each half, after Josip Ilicic's 12th-minute opener and Duvan Zapata's 56th-minute strike.

During United's lean run of form, there had been some criticism of Ronaldo for his defensive work, but he has now scored in every group game in this season's Champions League.

Ronaldo, 36, became the oldest player to score two or more goals in a game for United in European competition, having also matched Ruud van Nistelrooy's 2003 feat of scoring in four consecutive Champions League appearances.

"Some even managed to say he was a problem, imagine Ronaldo as a problem," Gasperini told Sky Sport Italia after the game. "He rarely gets it off target, half the time he scores, half the time it is saved."

The result leaves United top of Group F on head-to-head from Villarreal, with both sides on seven points, while Atalanta are third on five points approaching the final two matchdays.

Gasperini admitted deep regret at Ronaldo's opportunistic equaliser but continued to praise the United veteran, who has five goals in the Champions League group stage, along with four in the Premier League this season.

"The regret is one thousand. We believed in it," Gasperini said during his post-game news conference. "We believed in it because their thrust seemed a bit exhausted too.

"We had good spaces, we controlled the race well and was very close. But this is the Champions League. We faced an extraordinary player with incredible ballistic ability, he fired a shot on a bounced ball several times. This determined the result.

"We have to accept it anyway we still have some chances for qualification. It still depends on us. We played two games that have given a lot to us, to Atalanta and Bergamo."