Two first-half goals from Paul Scholes and Ashley Young condemned the Swans to a 2-0 defeat at Old Trafford in a critical weekend in the race for the Premier League title.
Despite the defeat, the Swans did themselves proud by pushing the defending champions and ensuring they endured a tough afternoon on their home patch.
With Manchester City winning at Newcastle earlier in the day, the onus was on United to make sure they were still in the title hunt going into the final weekend.
The Swans had started well, but Scholes deflected home Michael Carrick's shot before the half hour and when Young found the bottom corner minutes before the break the hosts were in danger of running away with the victory.
But the Swans, backed once again by their fantastic away support, dug deep and Gylfi Sigurdsson and Danny Graham went close to cutting the deficit in the second half and give the travelling Jack Army a goal to cheer.
It was United's day, but the Swans could again hold their heads high after putting in a performance which they could be proud of.
Brendan made three changes to the starting XI.
The Swans, free from relegation worries, included Mark Gower in the XI as Leon Britton could only make the bench after injuring his knee in midweek.
Angel Rangel made his return from a hamstring problem which saw him miss out against Wolves the previous week while fellow full-back Neil Taylor was also called back into the side, which meant Garry Monk was among the substitutes and Andrea Orlandi missed out.
Alan Tate was back on his former stomping ground as he was included among the substitutes against the club in which he had skippered the Youth and Reserve sides earlier in his career.
For the hosts, Danny Welbeck missed out along with Jonny Evans, though Rio Ferdinand and Phil Jones linked up in defence while Javier Hernandez led the attacking line with Wayne Rooney providing the support.
Manchester United: David De Gea, Patrice Evra (capt), Phil Jones, Rio Ferdinand (Rafael, 88), Chris Smalling, Michael Carrick, Ashley Young, Paul Scholes (Tom Cleverley, 68), Antonio Valencia, Wayne Rooney (Dimitar Berbatov, 79), Javier Hernandez.
Subs: Ben Amos,, Ryan Giggs, Park Ji-Sung, Nani.
Swans: Michel Vorm, Angel Rangel, Steven Caulker (Alan Tate, 90), Ashley Williams (capt), Neil Taylor, Mark Gower (Leon Britton, ht), Joe Allen, Gylfi Sigurdsson, Nathan Dyer (Luke Moore, 71), Scott Sinclair, Danny Graham.
Subs: Gerhard Tremmel, Garry Monk, Wayne Routledge, Josh McEachran.
The Swans settled into the encounter as well as Brendan would have hoped for.
The first 15 minutes passed with the Swans enjoying a fair share of possession while they also had the only real effort on goal as Nathan Dyer cut inside and fired over David De Gea's crossbar.
United went close with their first big threat when Antonio Valencia's corner fell to Patrice Evra, whose shot was kept out by Michel Vorm, and from the loose Wayne Rooney volleyed towards goal but again Vorm was on hand to swat it wide for another corner.
The Swans hit back when Gylfi Sigurdsson slipped a pass through to Danny Graham, but his weak effort was gathered by De Gea.
But it was United who got the opener just before the half hour as Valencia beat Neil Taylor and raced on before squaring to Michael Carrick, whose shot deflected in via Paul Scholes after 27 minutes.
The hosts went in search of another but Javier Hernandez nodded over after Ashley Young's cross found him in the box and then Rooney and Phil Jones tested Vorm.
But they did find the net again before the break - the Swans coughing up possession in their own box and when Angel Rangel's block on Rooney's shot fell to Young, the winger curled his effort into the far bottom corner.
The Swans replied with Gylfi Sigurdsson shooting straight at De Gea, but that was all the visitors could conjure as the whistle sounded for the break.
Half-time: Man Utd 2 Swans 0
Brendan made a change at the break with Leon Britton coming on in place of Mark Gower.
And the Swans were the first to probe, with Sigurdsson's bouncing shot just scrambled wide by De Gea for a corner.
Hernandez then headed over from Valencia's curling cross before the Swans went within inches of cutting the deficit. Sigurdsson's pass found Joe Allen, and his shot was diverted by Graham, but De Gea just managed to gather after taking the sting out of his goal-bound effort.
The Swans pushed again, Ashley Williams's fine pass to Sigurdsson on the halfway line saw the midfielder push on and spread left to Dyer, who cut back onto his right but blazed over from 15 yards.
Sigurdsson then went close himself, his fine curling 20-yard free-kick expertly tipped wide by De Gea as the visitors pushed strongly for a goal.
Luke Moore then replaced Dyer with 20 minutes to go as the Swans continued to push forward.
Rooney then chipped wide when through one-on-one with Vorm before Jones rose highest to nod Young's corner straight at Vorm.
The Swans then countered as Allen pinched possession off Carrick and sent Graham down the right flank. He cut inside his marker but shot straight at De Gea.
Alan Tate then came on in added on time for Caulker as he finally got his first competitive run out at Old Trafford.
But that was it at Old Trafford, as the Swans left with their heads held high but ultimately without a point as the champions ensured the title race remained on tenderhooks on the final day.