Rob Page's side secured an unlikely draw versus Group D favourites Croatia on Saturday, yet there was as much pressure to see off the minnows of the group.
Although they had the better of the game, it took a first-half header from Kieffer Moore to ensure that Wales made it four points from a possible six from their opening double-header.
Having struggled to create chances in Split at the weekend, Wales probably should have taken the lead during the early stages, but Harry Wilson was unable to convert at the back post having been found by Dan James.
Despite dominating the first quarter, Wales almost allowed Latvia to go in front through Marcis Oss, who brought a brilliant save out of Danny Ward after meeting a corner.
Latvia, who pushed Republic of Ireland all the way in a friendly last Wednesday, again went close through Vladislavs Gutkovskis, forcing Ward to react sharply to make a low stop.
However, four minutes before half time, the Dragons found a way to get their noses in front. James found Moore at the back post, giving the target man a chance to use his height to his advantage, and the Bournemouth man was able to power a header inside the near post from 12 yards.
With the momentum in their favour, Wales pushed for a second before the break, only for Harry Wilson to be denied by Pavels Steinbors who tipped his effort wide of the target.
Steinbors was at it again after the restart, somehow preventing Neco Williams from finding the top corner, but Gutkovskis reminded Wales that the game was not over with Ward called upon to make another timely intervention just before the hour mark.
As expected, Wales began to sit deeper, and it only encouraged Latvia to keep their hosts under pressure, yet their best chance of an equaliser came when Renars Varslavans blazed an effort off target from the edge of the area when having time and space.
Wales came through some nervy moments during the closing stages to claim their first win since the retirement of Gareth Bale, sitting second in the group behind Croatia on goal difference after the World Cup third-placed team defeated Turkey on away territory.