The 19-year-old fired home in the first half at the Superseal Stadium, adding to his goal in last week's win over Ross County, though Eamonn Brophy's strike levelled matters soon after.
Goalkeeper Freddie Woodman also played the full game for Killie, while winger Callum Roberts was an unused substitute.
In the Sky Bet Championship, Adam Armstrong got 90 minutes under his belt for Barnsley but they could only manage a 0-0 draw at home to Preston North End, while fellow frontman Ivan Toney picked up a yellow card as his Scunthorpe United side were beaten 3-1 at Southend United in League One.
Winger Alex Gilliead was an unused substitute as promotion-chasing Bradford City drew 2-2 at home to Gillingham, while in League Two, defender Macaulay Gillesphey played the full 90 minutes, helping 10-man Carlisle United grind out a 2-1 victory at Leyton Orient.
Young goalkeeper Paul Woolston, meanwhile, kept a clean sheet as Blyth Spartans recorded an emphatic 5-0 win at Ilkeston in the Evo-Stik Premier Division.
Further afield, Florian Thauvin was booked and then substituted in the 54th minute as Marseille were beaten 1-0 at Metz in Ligue 1, while Henri Saivet got a full game under his belt on his return from international duty as Saint-Etienne beat Lyon 2-0.
In the Eredivisie, Siem de Jong made an 84th-minute entrance as a replacement for Marco van Ginkel in PSV Eindhoven's 4-2 win at AZ Alkmaar, for whom goalkeeper Tim Krul played the full 90 minutes.
French forward Emmanuel Riviere played 78 minutes of Osasuna's 3-2 La Liga reverse at Real Sociedad, and Swiss defender Kevin Mbabu helped BSC Young Boys to a convincing 3-1 win over Sion in the Swiss Super League, playing the entire match.
OUT ON LOANAdam Armstrong – Barnsley (end of season)Macaulay Gillesphey – Carlisle United (end of season)Alex Gilliead – Bradford City (end of season)Ivan Toney – Scunthorpe United (end of season)Paul Woolston – Blyth Spartans (work experience loan)Sean Longstaff – Kilmarnock (end of season)Callum Roberts – Kilmarnock (end of season)Freddie Woodman – Kilmarnock (end of season)Siem de Jong – PSV Eindhoven (season-long loan)Tim Krul – AZ Alkmaar (season-long loan)Kevin Mbabu – BSC Young Boys (season-long loan)Emmanuel Riviere – Osasuna (season-long loan)Henri Saivet – Saint-Etienne (season-long loan)Florian Thauvin – Marseille (season-long loan)
