Ramos was playing his first game against Madrid since returning to the Spanish league last month with Sevilla, his boyhood club.
David Alaba scored an own goal to put Sevilla ahead in the 74th, but Dani Carvajal equalised with a header four minutes later.
Leaders Madrid were left three points ahead of second-place Girona and four points ahead of Barcelona in third before they play games on Sunday.
Ramos started his career with Sevilla but soon moved to Madrid, where he won 22 trophies in 16 seasons - including four Champions League titles - before leaving in 2021.
After two frustrating years with Paris Saint-Germain, the former Spain defender returned to Sevilla.
Ramos saved a goal-bound shot by former teammate Toni Kroos in the first half. The centre-back also had two late scoring chances to almost snatch the win for the hosts.
Ramos, who scored several big goals in his career for Madrid, almost bagged a winner from two headers with the score at 1-1. Kepa was able to push the ball onto his post, and Ramos later sent the ball high with his second header in stoppage time.
When the final whistle blew, Ramos embraced Madrid coach Carlo Ancelotti. The day before the game Ancelotti heaped praise on his former player, saying that Ramos' stoppage-time equaliser in the 2014 Champions League final was a key moment in his career.
"I loved seeing him again," Ancelotti said about Ramos after the game. "I said hello to him and wished him the best."
Shortly after the game, Sevilla said they had expelled a fan from their stadium and filed a complaint with police after the spectator allegedly displayed "xenophobic and racist behaviour." Sevilla did not specify what the behaviour was, or any intended target.
Madrid star Vinícius Júnior, who is black, has been targeted by racist abuse by rival fans on several occasions.
