Chris Wood came off the bench to inspire Burnley's second-half fightback which earned a 2-1 English Premier League win against Everton.
Wood, making his return after more than two months out with a knee injury, lost Ashley Williams to head the winner from a Johann Gudmundsson corner in the 80thminute.
Everton had been in a strong position to win the game at half-time, having taken a 20th-minute lead as Tosun guided a downward header past Burnley goalkeeper Nick Pope after Theo Walcott's cross had been glanced on by Seamus Coleman.
Burnley, seeking confidence after 11 league games without a win, might have wondered if they would be thwarted again, as Everton No 1 Jordan Pickford made four good saves in front of the watching England manager Gareth Southgate.
Pickford, a strong contender to start for his country when they play Holland and Italy in friendlies later this month, showed fine reactions to push away a Barnes chance in the first half, then keep out former Evertonian Aaron Lennon's first-time shot and Ben Mee's header soon after the interval.
The match turned when Michael Keane, the ex-Burnley defender, was caught on his heels as Barnes raced on to Matt Lowton's through pass to drive a shot past Pickford.
Sigurdsson created and then wasted a great chance to restore Everton's lead, slicing wide after manoeuvring his way through, before the home side took advantage of more defensive wobbling. Chris Wood, making his return as a substitute after more than two months out with a knee injury, jumped above Keane to head in Johann Gudmundsson's corner, and cement Burnley's standing in seventh place. That might be enough for Europe yet.
"The next game is the goal," said Turf Moor manager Sean Dyche. "It is a big marker to get to 40 with nine games to go. It took us a whole season last year. It takes the monkey off everyone's back."
