Brighton & Hove Albion romped to their biggest ever Premier League win, beating Wolverhampton Wanderers 6-0 despite resting key players as they continued their push for European qualification.
Undav registered his first Premier League goal after only six minutes, tapping in at close range, and Gross then netted twice, with his second strike a sensational volley from outside the box in the 26th minute.
Welbeck added a fourth before the break, heading in from Pervis Estupinan’s cross, as Brighton scored four goals in the first half of a Premier League match for the first time.
Wolves' head coach Julen Lopetegui made three half-time changes but Welbeck struck again within three minutes of the restart.
Undav then wrapped up the scoring with a wonderful chip over Jose Sa that kissed the bottom of the crossbar on its way into the net.
While Brighton remain eighth, they are now within two points of fifth-placed Tottenham Hotspur with two matches in hand. Wolves stay 13th on 37 points, eight points above the relegation zone.
Late heartbreak for Forest
Forest took the lead in first-half stoppage time when Danilo scored for a second successive match, reacting first to a loose ball and finishing from close range.
However, their lead evaporated when Ivan Toney scored his 20th Premier League goal of the season from an 82nd-minute free-kick.
Forest, who have won just one of their 17 away matches, stay 17th and will drop into the relegation zone on Monday night when Leicester City face Everton, with at least one of those sides guaranteed to pick up points.
Brentford stay ninth but move on to 50 points.
Palace climb above Chelsea
In a breathless first half, the first three shots all found the net, while five goals were scored in the space of just 27 minutes.
Tomas Soucek gave West Ham a ninth-minute lead from a corner, but Palace hit back through Jordan Ayew, Wilfried Zaha on his return from injury, and Jeffrey Schlupp, who made it 3-1 in the 30th minute.
West Ham then produced a response of their own five minutes later as Michail Antonio headed in from another corner.
In the second half, Eberechi Eze put Palace 4-2 up as he won and converted a penalty for his fourth goal in five matches.
Six minutes later, West Ham struck from a corner for the third time in the match as Nayef Aguerd headed in, but there was no late equaliser.
Bumper Sunday in store
Five matches will take place on Sunday with big permutations across the league.