Katie Kitching opened the scoring after 10 minutes before Asmita Ale scored her second of the season to bring the scores level at the break. Goals from Elise Hughes and Sanni Franssi then ensured the points would be staying in the North East.
Rick Passmoor made three changes that lost out to Newcastle last weekend, with Missy Goodwin, Paulina Nyström and Emilia Pelgander all coming in to the starting XI.
Even at the break
Asmita Ale got us back level in the first half.
The Foxes got off to the worst possible start when Kitching broke the deadlock, intercepting a pass from Katie Keane, who was off her line, allowing the Sunderland forward the opportunity to chip the Irish 'keeper from range.
Around 15 minutes later, we drew back level through Ale, who found herself in the right position, following a corner, and sent a dink over the crowd of players into the net.
As the game drew towards the interval, both sides looked to gain the advantage, but there was nothing to separate the sides at the referee's whistle.
Sunderland take charge
Two second half goals saw Sunderland take the points.
In the second half, it's fair to say the hosts looked the most likely to grab all three points, and retook the lead nine minutes after the restart through Hughes, who turned in a low and dangerous ball into the six-yard area.
Franssi then settled the scoreline a little after the hour mark when she had the time to control a cross into the box and fire past Keane.
City made changes to try and get back into the game, but the Black Cats, who remain second in Barclays WSL2, behind North East rivals Newcastle United, saw out the win, while we slip to eighth.
International break
International fixtures bring a pause to the WSL2 campaign.
A much-needed break now comes for the Foxes, with the first international break of the season up next in the schedule. Following four losses on the bounce, it provides an extra week for Passmoor and his side to prepare for the run-in to Christmas.
When the group returns together at Belvoir Drive, Leicester will head to The Hive Stadium, to take on Watford, on Saturday 17 October in the Subway Players Cup (3pm BST kick-off).