Wood, 22, prevented Unai Emery's Villa from scoring more goals after Jhon Duran pinched from Taylor Harwood-Bellis before holding off the former Swansea man and firing past Joe Lumley.
Southampton failed to register a shot on target for the second time on the road this season, the first occasion came during the 2-0 defeat to Wolves.
Here's how we rated every Saints player's performance at Villa Park...
Joe Lumley has conceded seven goals in three league games for SaintsJoe Lumley has conceded seven goals in three league games for Saints (Image: Jacob King/PA) Starters
Joe Lumley - 5.
Rushed off his line to deny Duran at 0-0 before handing Villa chances by passing into their press. Escaped his worst error when playing straight to Boubacar Kamara but conceded moments later. Made a good save with his feet in the second half.
James Bree - 5.
Kept his place at right-wing-back ahead of summer signing Yukinari Sugawara. Blocked a cross from Ian Maatsen in the first minute, setting the tone for the afternoon. Bombed on down the right but was not found by Flynn Downes as Saints delayed on the counter.
Nathan Wood - 7.
Saints would have lost by more goals had it not been for the 22 year old. Played a part in Duran's goal but made several blocks to keep a goal-hungry Villa at bay. Made three interventions in 10 second-half minutes as Southampton threw players forward. Stand out player in a poor team.
Nathan Wood was a standout at Aston Villa.Nathan Wood was a standout at Aston Villa. (Image: Jacob King/PA) Taylor Harwood-Bellis - 5.
Tried to control the ball under pressure from Duran before being pickpocketed by the Villa forward, allowing him to run through and score. Made blocks and headed clear to Tyler Dibling to start a counterattack.
Kyle Walker-Peters - 6.
Made an important block after Lumley played a poor pass into him, gifting the ball to Kamara and allowing John McGinn to shoot. Shifted to right-back after Bree was withdrawn at the break. One of three Saints players to create a chance.
Ryan Manning - 5.
Was solid enough, again without causing many problems. Had an early shot blocked behind for a corner during a good period for the away side. Registered zero per cent cross success rate and dribbles completed.
Flynn Downes - 5.
Passed straight out for a Villa corner within the first four minutes. Combined with Archer for a rare Saints chance, which was blocked. Saw his sixth yellow on his return from a yellow card suspension. Replaced for Ben Brereton Diaz with 10 to go.
Mateus Fernandes - 4.
Did little of real note. Struggled against a physical Villa midfield, leaving Saints light of attacking flair. Did not make a tackle and only completed one of his four dribbles. His effort can't be faulted and a level of consistency will come.
Mateus Fernandes had a difficult afternoon in the MidlandsMateus Fernandes had a difficult afternoon in the Midlands (Image: Jacob King/PA) Tyler Dibling - 5.
Martin felt it was his "worst" first-half performance for some time but he improved after the break. Caught the eye with a trademark drive which saw him feed Archer, but his effort was blocked.
Cameron Archer - 4.
Had two chances on his return to Villa Park but it was not a memorable game against his former side. Twice saw efforts blocked when Saints needed a goal. Applauded off by the home fans when he was subbed on 73 minutes.
Cameron Archer was an isolated figure on his return to Villa Park.Cameron Archer was an isolated figure on his return to Villa Park. (Image: Jacob King/PA)
Adam Armstrong - 4.
Wore the armband in Jack Stephen's absence. Caused Villa no problems on the break. Turned backwards every time he got into a dangerous area. Is not being used to his strengths - Saints do not play it into areas he can shine.
Substitutes
Joe Aribo - 5.
Came on at half-time as Martin shuffled the back, his introduction allowed Dibling to shift out to the right wing. Got up and down the pitch, as you would expect.
Sam Amo-Ameyaw - 6.
Came on for his first minutes since the opening game of the season. He immediately knocked a great ball into the box. Was booked after a good spin from Morgan Rogers. Hopefully the start of more minutes for the teenager.
Sam Amo-Ameyaw came on for his second league appearance of the season.Sam Amo-Ameyaw came on for his second league appearance of the season. (Image: Jacob King/PA) Ben Brereton Diaz - 4.
Failed to supply an impact from the bench. Was introduced for some height up front after Archer and Armstrong were unable to offer an out ball. Did work hard in the press but did little with the ball. Just six touches in 15 minutes.
Kamaldeen Sulemana - N/A.
Came on during additional time. Did beat his man down the left and looked to deliver into the box but his cross caused no problems.