Consistency in the second half of the season will decide the Premier League title, Manchester United and Arsenal agreed on Sunday after reeling in faltering leaders Chelsea.
"I think it's a mad league, a lot of teams are dropping points and it's really close," Manchester United striker Wayne Rooney said after scoring a goal, giving away another and setting up two more in a 3-1 win at struggling Hull City.
"Hopefully, we can be more consistent in the second half (of the season) and retain our title."
"It's looking different, that's for sure," United manager Ferguson told Sky Sports television after his side had cut Chelsea's lead to two points.
Wenger's Arsenal beat fourth-placed Aston Villa 3-0 to close within four points of Chelsea, and with a game in hand over the two clubs ahead of them. Chelsea were held 0-0 by Birmingham City on Saturday.
Already this season United have been surprised by Burnley and Fulham, Arsenal have lost at Sunderland and Chelsea came unstuck at Wigan Athletic.
"There are some unusual results going around...it's looking right now that it's going to be a very tight league," Ferguson said.
"I think the team that stays clear of injuries also will have an advantage.
"I'm hopeful that I will have all my defenders back by the time the European campaign comes around again which should freshen us up a bit. That will be important to us."
Ferguson had defenders Rafael da Silva, Nemanja Vidic and Wes Brown returning from injury at Hull, allowing Darren Fletcher to return to midfield alongside Michael Carrick.
MENTAL STRENGTH
Arsenal had second-half substitute Cesc Fabregas to thank for two goals but the Spaniard, returning from a hamstring injury, limped off six minutes from time in a further injury concern for Wenger.
The Frenchman, likely to look for a new striker in the January transfer market because of Robin van Persie's long-term injury, praised his men for their determination.
"I think it is a massive result for the team if you look where we were a few weeks ago. And credit to the team, they didn't give up when everybody had written them off and kept going," he said.
"The team has shown great mental strength."
"This team is talented, is hungry, has a great spirit and for me they deserve to be successful. But we have not won anything yet," added Wenger.
"We are in a strong position, but of course it is a long way to go and we have to keep our feet on the ground and continue to improve. From now on until March in this championship, the most consistent team will win."
