An Aiden McGeady brace saw Sunderland climb into the automatic promotion slots in League One.
Here's what we learned from the 2-0 win.
Sunderland still to hit top form
It sounds odd, given the Black Cats have just won six games on the spin - five in the league and one in the Checkatrade Trophy - with four clean sheets along the way.
But there is still a big improvement to come, you feel, from this team. And that is a daunting prospect for their League One rivals.
The first half display was average, Sunderland's play in their final third too predictable and lacking cutting edge. They were playing too narrow.
Sunderland started the second half with far more purpose, their passing was quicker and slicker and in the likes of Aiden McGeady they always have matchwinners.
Sunderland have scored in every game so far this season, now they have sorted out the clean sheets at the other end, it makes them a very dangerous side.
Jon McLaughlin's role cannot be understated.
He arrived on a free and has so far proved the signing of the summer. Mr Dependable.
Fresh from the birth of his second child, McLaughlin hot-footed it to Plymouth to help Sunderland record their fourth straight clean sheet.
McGeady will grab the headlines but the keeper's role cannot be understated. The Scot made two vital saves, first to palm away a goalbound free-kick and then a minute later diving low to keep Sunderland's 1-0 lead intact.
Given the dross in goal last season, the sight of McLaughlin's name on the teamsheet gives such a boost to those he plays with and those watching from the terraces.
The King has an off day.
It is a difficult label to live up to every game and this was one of those games for Chris Maguire.
Fresh from his wonder goal against Southend United last weekend, Maguire was deployed in the hole, behind Josh Maja at Plymouth.
His influence on the game was not to his usual standard and it was no surprise to see him subbed.
He did draw a good save from Matt Macey first half but he wasn't able to have as much influence as usual.
Luke O'Nien impresses from the bench again.
Jack Ross spoke in-depth about his use of his Sunderland subs in the build-up to the game, the Scot not afraid to make early, bold, game changing decisions.
He didn't need to make an early sub at Plymouth given McGeady put Sunderland in front just eight minutes into the second half.
But one sub that has made a consistent positive impact in recent games is O'Nien.
Full of energy and legs, he has now settled into life at Sunderland and his performances are improving, keen to get forward and burst into the penalty area.
He won the penalty, from which McGeady stepped up to seal the three points. It just shows the strong options from which Ross can call upon.
Dylan McGeouch influence growing.
At Home Park, the Scot enjoyed his best game for Sunderland.
Deployed in one of the two holding midfield roles alongside skipper George Honeyman, McGeouch's impressive display lessened the blow of Lee Cattermole's absence.
Calm in possession, there is an intelligence about his play and he rarely wastes a pass. His defensive work has also been important in recent games and can go under the radar.
Against Plymouth he made three important blocks. His influence on this team grows by the week.
Sunderland fanbase rewarded on longest away day.
It's an 806-mile round trip to Plymouth Argyle's Home Park stadium from Wearside. The longest away trip of the season. Sunderland, again, sold out their allocation.
They were given more tickets on top. Just shy of 1,400 fans witnessed the sixth straight win. Six in a row has a nice ring to it for Sunderland fans.
The away fans were housed in the stand behind the goal, to their left the main stand which is undergoing a major refurb having been gutted ahead of redevelopment.
It made for an eye catching backdrop on another entertaining League One away day. Sunderland fans are enjoying themselves and long may it continue.