Manchester United delivered a fitting tribute to George Best as they cruised into the last eight of the Carling Cup.
After an emotional pre-match build-up, two quick goals from Cristiano Ronaldo and Louis Saha set up an easy win.
Ronaldo scored from the spot in the 12th minute after he was fouled by Diomansy Kamara, and Giuseppe Rossi set up Saha four minutes later.
John O'Shea added a fine third after 56 minutes before Nathan Ellington pulled a goal back for West Brom late on.
Old Trafford staged a perfectly observed minute's silence prior to the game, with United stars past and present paying tribute to Best.
Manchester United manager Sir Alex Ferguson, perhaps sensing the poignancy of the occasion, selected a strong side, with Gary Neville, Rio Ferdinand and Saha in the starting line-up and Wayne Rooney on the bench.
It was one of United's youngsters, Rossi, who made an early impression, setting up Saha after a powerful run into the box, but the French striker's finish was ruled out for a marginal offside decision.
But an expectant Old Trafford crowd did not have long to wait for the opener when Kamara tripped Ronaldo in the area after 12 minutes, and the young Portugal international calmly stroked home the spot-kick.
The gifted Rossi, who is hugely admired by boss Ferguson, turned creator four minutes later when he delivered a perfect pass for Saha to fire in a shot from 20 yards which keeper Russell Hoult should have saved.
Kamara had a chance to put Albion back in contention after good work by Geoff Horsfield on the right flank, but he blazed over.
But Rossi was the star of the first 45 minutes, and he almost crowned an outstanding performance with a shot that hit the base of the post from Saha's pass.
O'Shea's glorious solo effort, his second in successive games, wrapped up United's win 11 minutes after the break.
He took a return pass from Saha before controlling and striking a powerful finish past Hoult.
The three-goal margin gave Old Trafford the chance to concentrate on paying homage to Best, which they did in style.
West Brom continued to battle and they pulled a goal back after 77 minutes when Ellington headed home Darren Carter's corner - but United were never troubled and took their place in Saturday's draw.
Manchester United manager Sir Alex Ferguson:
"The fans were fantastic. They paid a fitting tribute to George Best and the result was good as well.
"We knew it was going to be tough because West Brom have been playing well, but we acquitted ourselves well. Two of the goals were exceptional and I thought some of our play was fantastic at times.
"It was good to see Louis Saha back and scoring a goal. He is a fantastic, top striker. We all know about his ability and now I just hope and pray he stays fit.
"We will have a go at winning this. There are some good teams left and we'll see what the draw brings."
West Brom manager Bryan Robson:
"We gifted them the game. We played some very good attacking football, but let ourselves down with some bad defending.
"The first two goals we gave away were really poor and bad defending. In the first attack United had we were rash and gave away a penalty.
"We had two people on Ronaldo when he received the ball and we went diving in unnecessarily to give them the penalty."
Man Utd: Howard, Neville, Ferdinand, Silvestre, O'Shea (Pique 67), Ronaldo, Fletcher (Jones 59), Park (Bardsley 63), Richardson, Rossi, Saha.
Subs Not Used: Rooney, Steele.
Goals: Ronaldo 12 pen, Saha 16, O'Shea 56.
West Brom: Hoult, Albrechtsen, Moore (Gaardsoe 45), Clement, Robinson, Kamara (Earnshaw 70), Wallwork, Carter, Inamoto, Horsfield (Chaplow 66), Ellington.
Subs Not Used: Greening, Kuszczak.
Goals: Ellington 77.
Ref: M Clattenburg (Co Durham).