Leeds overcame wantaway striker Chris Wood's absence to maintain their unbeaten start to the Sky Bet Championship campaign with a 2-0 win at Sunderland.Wood, who is reportedly closing in on a move to Premier League side Burnley, was not even in Thomas Christiansen's squad for the fixture at the Stadium of Light.However, being without the New Zealand international had little impact on his team-mates as Leeds produced a controlled display to claim the points.Both sides entered the contest having not tasted defeat this term, although only Christiansen's men could boast such a record at full-time.The visitors had the better of an entertaining opening period and entered the break ahead thanks to Saiz Alonso's 21st-minute strike.An exceptional evening's work was capped with 14 minutes remaining when substitute Stuart Dallas nodded home a decisive second.United skipper Liam Cooper returned from injury in one of two changes, with Caleb Ekuban taking Wood's place, while Sunderland boss Simon Grayson named an unchanged side against his former club.Such continuity was evident during the opening exchanges, with Brendan Galloway's superb centre across the six-yard box just eluding Lewis Grabban.Leeds grew in stature thereafter as the game took on an end-to-end nature, although it was the hosts who created the next big opening.Grabban followed his own long ball to take a return pass from strike partner James Vaughan, only to see a goal-bound effort deflected on to the crossbar by Cooper.That miss loomed large moments later as Leeds flipped the script to move ahead.Ezgjan Alioski found space on the right wing and pulled the ball back to Saiz, who capped his sublime late run by controlling the ball and calmly stroking into the bottom corner.Suddenly brimming with confidence, the visitors almost grabbed a second when Alioski crossed for Pablo Hernandez, who headed wide.His frustration was compounded by being withdrawn due to injury immediately after, but Leeds barely skipped a beat as they controlled proceedings until half-time.The visitors' stretched forward resources were tested further after the interval when Ekuban also limped off, replaced by Dallas.That came amid some good moments for Sunderland, whose eye-catching play was only undermined by a final ball that left much to be desired.Their profligacy was almost punished in the 70th minute when the ever-dangerous Alioski's 20-yard free-kick forced a smart save from Jason Steele.The keeper could do nothing soon after, however, as Leeds wrapped up the points when Saiz sent in a superb cross which Dallas, unmarked at the far post, headed into the net.