London: Lincoln City produced a huge FA Cup shock to beat top-flight Burnley 1-0 away and become the first minor league club to reach the quarterfinals for 103 years on Saturday.
On a day of fifth-round toil for the top flight sides, English champions Leicester City's problems continued to mount as they went down 1-0 at third-tier Millwall, who played most of the second half with 10 men.
Premier League Middlesbrough restored some order, quelling a comeback by third-tier Oxford United to win 3-2 at the Riverside Stadium but Pep Guardiola's Manchester City were held 0-0 at Championship side Huddersfield Town.
In the late kick-off on Saturday, Chelsea marched into the last eight after defeating Wolverhampton Wanderers 2-0 with goals from Pedro and Diego Costa.
Millwall's third win over Premier League opposition this season, secured by Shaun Cummings's 90th-minute goal at the New Den, would ordinarily have topped the shocks.
But they were outdone by Lincoln.
Sean Raggett's headed goal in the 90th minute continued the run of the National League leaders who easily matched Burnley, a side 81 places higher up the English football ladder and who held Premier League leaders Chelsea to a draw a week ago.
"It's a football miracle for a non-league team to be in the last eight," Lincoln's young manager Danny Cowley said. "We are realists. I will never ask the players to do something they're not capable of. But we thought if we could get the game plan right we could compete."
Burnley had only lost three of their previous 29 home matches in all competitions, but failed to make their perceived superiority show in a scrappy game.
Just when it seemed Burnley had gained the upper hand Lincoln were awarded a corner and Raggett rose above a crowd of players to head the ball over the line despite keeper Tom Heaton's attempt to claw it out.
Lincoln, only the third minor league side to beat top flight opposition in nearly 30 years, are now just one win away from a semi-final at Wembley Stadium.
Burnley, meanwhile, were the fall guys again having been beaten by minor league Wimbledon in 1975 when they were also a top flight side. "My team were nowhere near the level they can show," manager Sean Dyche said.
Leicester manager Claudio Ranieri made 10 changes for his side's trip to south London Millwall - his eyes fixed on the champions' relegation battle and a looming Champions League last-16 tie against Spanish club Sevilla.
Millwall had Jake Cooper sent off in the 52nd minute for a second booking but even a numerical advantage failed to stir a Leicester side who suffered a sucker punch when Cummings was played in by Lee Gregory and fired past Ron-Robert Zieler.
"When it was 10 versus 11 they played better than us with more desire and heart and deserved to win," Ranieri, whose side have lost five consecutive league games, said.
Chris Maguire and Toni Martinez scored within a minute of each other to haul Oxford level at Middlesbrough but their hopes of emulating Lincoln and Millwall were ended four minutes from time when Cristhian Stuani tapped in Boro's winner.
Promotion-chasing Huddersfield enjoyed a record crowd of 24,000 at their John Smith's Stadium as they matched Guardiola's City. "A clean sheet against Manchester City makes our chest bigger," Huddersfield boss David Wagner said.
