The 18-year-old midfielder showed remarkable poise to beat experienced keeper Andres Palop twice in one-on-one situations, lobbing in for the first goal after 25 minutes and dribbling past him on a breakaway for the second before halftime.
Canales was applauded by both sets of fans when substituted midway through the second period, by which time Sevilla had cut the deficit after Ndri Romaric bundled the ball in at a corner.
Sevilla pressed hard but were denied by the woodwork and a couple of spectacular saves from Racing keeper Fabio Coltorti. The home team were booed off by disgruntled fans at the end.
A third straight league defeat left Sevilla fifth in the standings with 30 points, 10 behind leaders Barcelona and eight adrift of second-placed Real Madrid.
Real play fourth-placed Real Mallorca at the Bernabeu on Sunday when Barca visit lowly Tenerife.
"We knew it was going to be tough in January but not this tough. We played a disastrous first half," Sevilla coach Manolo Jimenez told reporters.
"We are missing a lot of players but that is no excuse. We are losing games because of our own failings rather than through the merits of our rivals."
Atletico Madrid put their embarrassing midweek King's Cup first leg defeat behind them to crush Real Valladolid 4-0.
ATLETICO REACTION
Coach Quique Sanchez Flores criticised his team's attitude after they lost 3-0 at second division strugglers Recreativo Huelva on Wednesday and they responded with a vastly improved display in Valladolid.
Jurado put away a Jose Antonio Reyes lay-off after 16 minutes and Diego Forlan broke to double the lead in the 32nd.
Reyes capped an industrious performance with a superb volley from outside the area after the break and substitute Sergio Aguero returned from a month out injured to score the fourth.
"I'm delighted my players have reacted and today we saw them at their best," Sanchez Flores told reporters. "We couldn't have played any worse than we have been doing."
In the late game, Villarreal were held to a 1-1 draw at home by Almeria with Corona's second-half penalty cancelling out Nilmar's 40th minute header.
Villarreal are ninth with 23 points. Atletico are 11th with 20, one ahead of Racing in 12th.
