Welsh Premier League champions The New Saints have broken a 44-year-old world record for the longest winning streak in top-flight football.
Friday's 2-0 win at Cefn Druids was their 27th in a row in all competitions - one more than Dutch giants Ajax in 1971-72.
TNS have won all 21 of their league games, four in two Welsh cups and two in the Scottish Challenge Cup, in which they were invited to play this season.
The New Saints - full name The New Saints of Oswestry Town & Llansantffraid Football Club (Welsh: Clwb Pêl-droed y Seintiau Newydd) - are both a Welsh and an English side, representing the village of Llansantffraid-ym-Mechain in Powys, Wales, and the town of Oswestry in Shropshire, England, which are just eight miles apart.
Welsh Premier League: Champions The New Saints break Ajax world record
By Tom Brown
BBC Wales Sport at The Rock, Wrexham
30 December 2016
Welsh Premier League record breakers The New Saints
Welsh Premier League champions The New Saints have broken a 44-year-old world record for the longest winning streak in top-flight football.
Friday's 2-0 win at Cefn Druids was their 27th in a row in all competitions - one more than Dutch giants Ajax in 1971-72.
TNS have won all 21 of their league games, four in two Welsh cups and two in the Scottish Challenge Cup, in which they were invited to play this season.
They have also won the Welsh domestic treble in the last two seasons.
Scottish fifth-tier side East Kilbride thought they had broken Ajax's record earlier this season - but the official mark can only be set by teams playing in their country's top tier.
A 4-0 win to TNS in the reverse fixture on Boxing Day suggested another victory over Cefn Druids on Friday night would be a formality.
But some resolute defending in the first half from the home side suggested they were in the mood to spoil the party.
However, TNS' Aeron Edwards broke the deadline after half an hour and Jon Routledge struck with a late long-range effort to seal the win and the new world record.
Harrison's side last suffered defeat in July when they were beaten 3-0 by Apoel Nicosia of Cyprus in a Champions League second qualifying round second leg tie.
The record
Johan Cruyff was a member of the Ajax side which won the European Cup in 1972
The previous benchmark was set by Dutch giants Ajax in 1972, by a side which included the legendary Johan Cruyff and Johann Neeskens.
The Amsterdam club won 26 games in a row in all competitions, including 19 league wins in the Eredivisie, four European Cup victories and three Dutch Cup wins.
Ajax came within one game of equalling the record during the 1995-96 season when a side featuring Edwin van der Sar, Frank and Ronald de Boer, Edgar Davids and Jari Litmanen won 25 games in a row.
Brazilian side Cortiba won 24 straight games in 2011 and Real Madrid - including Wales forward Gareth Bale - won 22 consecutive games during the 2014-15 season.
Scottish side East Kilbride actually went on a longer winning run earlier this season, with 30 consecutive wins, and received a crate of beer from Ajax in recognition.
But their feat has not been recognised by Guinness World Records as they play in the fifth-tier Lowland League.
Welsh Premier League: Champions New Saints break Ajax world record - BBC Sport
Friday's 2-0 win at Cefn Druids was their 27th in a row in all competitions - one more than Dutch giants Ajax in 1971-72.
TNS have won all 21 of their league games, four in two Welsh cups and two in the Scottish Challenge Cup, in which they were invited to play this season.
The New Saints - full name The New Saints of Oswestry Town & Llansantffraid Football Club (Welsh: Clwb Pêl-droed y Seintiau Newydd) - are both a Welsh and an English side, representing the village of Llansantffraid-ym-Mechain in Powys, Wales, and the town of Oswestry in Shropshire, England, which are just eight miles apart.
Welsh Premier League: Champions The New Saints break Ajax world record
By Tom Brown
BBC Wales Sport at The Rock, Wrexham
30 December 2016
Welsh Premier League record breakers The New Saints
Welsh Premier League champions The New Saints have broken a 44-year-old world record for the longest winning streak in top-flight football.
Friday's 2-0 win at Cefn Druids was their 27th in a row in all competitions - one more than Dutch giants Ajax in 1971-72.
TNS have won all 21 of their league games, four in two Welsh cups and two in the Scottish Challenge Cup, in which they were invited to play this season.
They have also won the Welsh domestic treble in the last two seasons.
Scottish fifth-tier side East Kilbride thought they had broken Ajax's record earlier this season - but the official mark can only be set by teams playing in their country's top tier.
A 4-0 win to TNS in the reverse fixture on Boxing Day suggested another victory over Cefn Druids on Friday night would be a formality.
But some resolute defending in the first half from the home side suggested they were in the mood to spoil the party.
However, TNS' Aeron Edwards broke the deadline after half an hour and Jon Routledge struck with a late long-range effort to seal the win and the new world record.
Harrison's side last suffered defeat in July when they were beaten 3-0 by Apoel Nicosia of Cyprus in a Champions League second qualifying round second leg tie.
The record
Johan Cruyff was a member of the Ajax side which won the European Cup in 1972
The previous benchmark was set by Dutch giants Ajax in 1972, by a side which included the legendary Johan Cruyff and Johann Neeskens.
The Amsterdam club won 26 games in a row in all competitions, including 19 league wins in the Eredivisie, four European Cup victories and three Dutch Cup wins.
Ajax came within one game of equalling the record during the 1995-96 season when a side featuring Edwin van der Sar, Frank and Ronald de Boer, Edgar Davids and Jari Litmanen won 25 games in a row.
Brazilian side Cortiba won 24 straight games in 2011 and Real Madrid - including Wales forward Gareth Bale - won 22 consecutive games during the 2014-15 season.
Scottish side East Kilbride actually went on a longer winning run earlier this season, with 30 consecutive wins, and received a crate of beer from Ajax in recognition.
But their feat has not been recognised by Guinness World Records as they play in the fifth-tier Lowland League.
Welsh Premier League: Champions New Saints break Ajax world record - BBC Sport