Things looked to be going to plan against the league leaders when Danny Rose was fouled in the penalty area 10 minutes into the second half and Tom Huddlestone buried the spot kick for a 1-0 lead.
But Villa equalised within a minute and then took control of the game to win 3-1 with goals from Tobias Mikaelsson (2) and Marlon Harewood.
"I said the lads afterwards that it was if the hard work was done because we got ourselves in the lead," reflected Clive at Walsall's Banks's Stadium. "After that we gave up opportunities that we hadn't done in the first hour of the game.
"The way we conceded the goals was poor and I felt we lost our discipline through sheer frustration.
"It looks like a heavy defeat and we haven't had a defeat away from home for a very long time.
"We don't like losing, it was disappointing but there were some positives in there as well. It's important now that we learn when things don't go right."
Those positives included a return to action for Dorian Dervite after recovering from a serious knee injury in January, a 20-minute stint off the bench.
"It was great to see Dorian back, Joe Martin also played after a long-term injury and both will be better for playing," added Clive. "I also thought Danny Rose played well in his first 90 minutes for us and Troy Archibald-Henville was up against Marlon Harewood, a tough, physical game for him and he came through it well."
Clive Allen felt Villa's quick response to going behind proved a turning point in Monday's reserve clash.