Marcelo Bielsa was left to rue poor Leeds finishing as his side suffered a 2-0 defeat at Champions League hopefuls West Ham on Monday night.
Jesse Lingard sparked West Ham into life when his run into the penalty area drew a foul from Luke Ayling. Lingard converted the rebound after his spot-kick was saved by Illan Meslier.
Leeds had found the net twice in a blistering opening spell, but Tyler Roberts’ finish was ruled out for a marginal offside against Helder Costa, and Raphinha ran the ball out of play before crossing to Patrick Bamford.
But the visitors were two goals down before half-time when the unmarked Craig Dawson headed in Aaron Cresswell’s corner.
Leeds continued to squander chances in the second period, with Patrick Bamford the main culprit, as the Hammers ended up with a valuable three points.
Speaking after the game, Bielsa told Sky Sports: “In the initial 15 minutes we were very good. In the final 30 minutes of the first half we defended poorly. In the second half we defended well and attacked well.
“We played better in the second half than they did in the first half. The differences in the first half were smaller than in the second half.
“We created 10 opportunities at goal without taking into account the disallowed goals. They were sufficent to deserve a different result.
“I don’t ignore in those 30 minutes they created danger that was important. In the hour we were the dominant side we were superior than West Ham were in the 30.”