Ronaldo, who had earlier finished off a flowing team move to cancel out Josip Ilicic's opener, rescued a point for Ole Gunnar Solskjaer's side with a stunning volley in the second minute of stoppage time after Duvan Zapata had put Atalanta back in front.
Ronaldo's latest heroics come just two weeks after he scored the winner in the reverse fixture against Atalanta at Old Trafford and his double takes him to nine goals in 11 appearances this season following his strike against Tottenham on Saturday. His sensational second goal, crashed home from the edge of the Atalanta box, made the 36-year-old the oldest player in Manchester United's history to score twice in a single European game, and Merson feels there is plenty more to come from him.
The 36-year-old just loves the Champions League and he looked in the mood right from the start of this game, testing Atalanta's Juan Musso with a long-range effort inside the first minute. From then on, however, he only appeared sporadically. Ronaldo had 50 touches over the course of the 90 minutes, but many of them were in areas in which he was unable to hurt Atalanta as United showed a familiar lack of cohesion.
United Coach, Solskjaer looked to one of the NBA's finest-ever players to draw a comparison with the ex-Real Madrid and Juventus ace, even though he admitted he was not overjoyed to see Ronaldo pass his own goal tally for the Red Devils. "That last goal there, that must be a Michael Jordan moment when he wins championships in extra time. No-one can question the attitude and character of these players, they never give up, and sometimes we play better than tonight but as long as I see that attitude every time, the quality will come." He said.
The draw puts United top of Group F, above second-placed Villarreal ahead of their trip to face the Spanish outfit later this month, but Solskjaer's side were once again poor for long periods of the game.
A big weekend victory over Tottenham and now this draw appears to have shored up Solskjaer's position, which seemed less than secure in the wake of the 5-0 defeat at the hands of Liverpool. The Norwegian cannot afford to rest on his laurels though, as the big games continue to come thick and fast in November.
On Saturday the Reds welcome derby rivals Manchester City to Old Trafford in the Premier League, while after the international break visits to Watford and Chelsea as well as Villarreal in a crucial Champions League clash loomed large.