Watts - a 19-year-old defender - played a key role for the Boro against Leyton Orient, keeping a clean sheet during a 0-0 draw at the Breyer Group Stadium, with the teenager playing the full 90 minutes during an impressive senior league debut.
Despite the loss of Stevenage centre-back and captain Scott Cuthbert on 36 minutes, Orient were unable to find a breakthrough against an organised Stevenage side, who picked up their first league point of the season.
Elsewhere, Sørensen was unable to make a goalscoring mark in his first Carlisle appearance as the Cumbrians suffered a 2-0 home defeat against Mansfield Town.
The Danish forward replaced Harry McKirdy after 56 minutes but struggled to make an immediate impact as first-half goals from Danny Rose and Nicky Maynard sealed the Stags' first victory of their League Two campaign.
Goalkeeper Freddie Woodman, meanwhile, was involved in a five-goal thriller with Swansea City as the Swans came from behind during a 3-2 win over Preston North End, maintaining their unbeaten start to the Championship, while midfielder Dan Barlaser played 72 minutes of Rotherham United's 1-0 away victory at Burton Albion.
However, Jacob Murphy was unable to continue a 100 per cent winning record with Sheffield Wednesday following the Owls' 1-0 defeat to ten-man Millwall at the Den.
And young shot-stopper Nathan Harker was involved between the sticks during Blyth Spartans' 1-0 home defeat to Hereford in the National League North.