The 18-year-old striker had a dream debut, scoring just five minutes after he was introduced to proceedings - with less than 15 minutes left on the clock - to earn the Black Cats their first victory in front of their own fans in all competitions since December 17, 2016.
Combined with other results, the victory lifts Chris Coleman's side out of the Championship relegation zone and up to 21st in the table.
Burton Albion moved off the bottom and to within one point of safety after Lloyd Dyer's early goal proved the difference in their relegation clash at Bolton Wanderers, a result that saw the Trotters drop down to 23rd.
Having beaten Sheffield Wednesday last night, Wolverhampton Wanderers continue to lead the way at the top of the table with a seven-point advantage over Cardiff City, who welcome Hull City to Wales in today's late kickoff.
Bristol City continue to apply the pressure on the top two courtesy of a 2-1 victory over Nottingham Forest, moving them to one point of the automatic promotion places, while goals from Andreas Weimann and Johnny Russell helped Derby County to a 2-0 victory over Aston Villa.
Sheffield United's poor run of form continued as they lost 1-0 away at Preston North End - their fourth defeat in five - and waiting to capitalise, Leeds United produced a 1-0 victory over Norwich City courtesy of Pontus Jansson's first-half header to move one point off the playoffs.
Championship results in full: Birmingham City 1-2 Queens Park Rangers, Bolton Wanderers 0-1 Burton Albion, Brentford 0-0 Barnsley, Bristol City 2-1 Nottingham Forest, Derby County 2-0 Aston Villa, Ipswich Town 2-0 Reading, Leeds United 1-0 Norwich City, Millwall 2-1 Middlesbrough, Preston North End 1-0 Sheffield United, Sunderland 1-0 Fulham