The Portugal forward, top scorer in the competition this season with 13 goals, netted for the sixth time in three games in all competitions by finishing off substitute Lucas Vazquez’s cross at the near post after 64 minutes.
Four minutes later Ronaldo, who put Real on the way to a 2-0 win in the first leg of the last-16 tie with a stunning strike, released Rodriguez with a delicate pass and the Colombia forward prodded the ball between the legs of keeper Wojciech Szczesny.
“It was a difficult game even though some people didn’t expect it would be, but in the end we achieved our objective, which was to go through, and we didn’t concede a goal,” Real coach Zinedine Zidane told a news conference.
Real’s Keylor Navas kept his sixth straight Champions League clean sheet to move ahead of former Manchester United stopper Edwin van der Sar with the second-longest run in the competition without conceding a goal and is now unbeaten in 540 minutes.
Roma coach Luciano Spalletti said before the game that he was “asking for the impossible” from his side as they looked to overturn the deficit surrendered at the Olympic Stadium, but they had two clear chances to take the lead before the break.