Manchester United returned to the top of the Premier League table with a 2-0 win over West Brom, while Manchester City couldn't avoid defeat against Swansea City, and there was plenty on show to learn for both the Red Devils and the Baggies at Old Trafford.

United's goals both came via Wayne Rooney, while Jonas Olsson was dismissed for two yellow cards for West Brom.

The away side started the brighter and went close through Keith Andrews, but United dominated possession for huge tracts of the game and deservedly led at halftime.

After the break, the away team threatened only intermittently, and though they had half a penalty shout when Peter Odemwingie went down in the box, it was United who won the game's only penalty and dispatched it with consummate ease to seal the points.

Here are five things we learned from today's game.

West Brom's Attacking Quartet Mean a Top-Half Finish Is a Possibility

West Brom started the game very well against Manchester United before fading away, but they have shown over the past month that they have enough in the final third to trouble plenty of sides.

Against United, they cut through midfield and defence a number of times in the opening spell before sitting back and conceding massive amounts of possession.

Peter Odemwingie, James Morrison, Chris Brunt and Shane Long are four very talented players for Roy Hodgson's side, with Morrison in particular enjoying the form of his life this season.

Long was left out against United in favour of the more robust Marc-Antoine Fortune, but Long has the knack of getting goals, especially against sides around West Brom in the table, which could see them achieve their best top-flight finish since the early 1980's. They will do this should they end the campaign in the top half.

Wayne Rooney Is the Only Serious Threat to Robin Van Persie's Golden Boot

Wayne Rooney scored a brace of goals against West Brom to leave him clear in second place in the race for the Golden Boot award, with 18 goals from his 23 Premier League appearances.

While he is still some distance off Robin van Persie—25 goals in 27 appearances—he is certainly the only one showing consistent goal scoring form who could realistically trouble the Dutchman.

United are scoring goals aplenty, and Rooney is in great form; van Persie has the edge for now, but his constant need to be the Arsenal supplier of goals might start to turn on his team for the worse in the remaining two months of the season.

Tom Cleverley Returning from Injury Is a Big Boost for Manchester United

Tom Cleverley entered the pitch with a little over 10 minutes to play at Old Trafford against West Brom to a general good reception from the United fans.

Only his fifth Premier League appearance of the season, Cleverley has already captured the imaginations of the Red Devils supporters who see him as the creative hub of their midfield for seasons to come.

His setbacks with injuries earlier on in the season appeared to cost United dearly at the time, with Wayne Rooney forced to play in midfield for several games before Paul Scholes came out of retirement to fill the hole.

Cleverley's latest comeback will be a welcome sight for Alex Ferguson, while Cleverley himself will still harbour ambitions of breaking into England's Euro 2012 squad—though he needs to remain fit from here on in to have a chance, with fellow young midfielder Jack Wilshere out injured for the whole season.

Referees' Penalty Decisions at Old Trafford...Again

Lee Probert was the man in the middle for the match between Manchester United and West Brom, and though by and large it was an inoffensive match with few flashpoints, there were two instances in particular which would make the supporter of the away side think, "here we go again!"

Not the red card—Jonas Olsson's second yellow card was a reckless sliding tackle, and he thoroughly deserved to walk.

But the two penalty incidents.

At one end, Patrice Evra clearly made contact and tripped Peter Odemwingie; the appeal was waved away.

I'm not saying it was a definite penalty...but you have certainly seen them given. Odemwingie was past Evra, and the Frenchman's foot got in the way of the forward.

Nothing doing, though; fair enough.

But a few minutes later, Ashley Young blazes past a defender, feels the merest of touches on his back and goes crashing to the ground...not a moment's hesitation, and the referee signals a penalty.

It was a long way from that straight a call, and for me, was less of a foul than the Evra/Odemwingie situation.

United had so much control over the game that they should have won by several goals—but that's not the point.

West Brom could have been level at 1-1 had they scored their own penalty, with not all that long to play.

Of course, then there would have been an additional six minutes of injury time to deal with...

United Back on Top, City's Turn to Do the Chasing

With 10 matches to go until the end of the season, Manchester United have overhauled their neighbours at the top of the table and lead by a single point.

After leading for so long, it will be a big blow for Roberto Mancini and his Manchester City side, but could it actually benefit them?

City, as has been pointed out so often, have no experience in this kind of title run-in, and chasing is frequently claimed to be easier than leading.

United have the mentality to keep winning their own matches, and next week could be a real indication of just how hard City are going to push them—they host Chelsea at home, while United travel to the woeful Wolverhampton Wanderers.