Ephron Mason-Clark's goal was his second in as many games for Coventry City
Frank Lampard collected his first win as Coventry City boss as his Sky Blues side won 1-0 at Millwall in the Championship.
Millwall had an early goal direct from Joe Bryan's corner disallowed for a foul on goalkeeper Brad Collins, but otherwise it took 30 minutes for either team to produce any effort of note.
Coventry should have been celebrating after an hour, only for Ephron Mason-Clark's close-range effort to be well saved by Lukas Jensen, but they only had to wait four more minutes for the forward to put his side ahead as he converted Jack Rudoni's cross.
Bobby Thomas almost doubled the lead but his 86th-minute header rattled the Millwall post.
However, the result ended a five-game winless run for Coventry, who brought in former Chelsea and England midfielder Lampard to replace long-serving boss Mark Robins last month.
It lifts the Sky Blues up to 14th in the Championship, while Millwall remain in 11th place after a first loss in 10 games.
Frank Lampard is unbeaten as Coventry City head coach after a 2-2 draw with Cardiff City in his first game last week
Fans and players paid tribute to former Lions boss John Docherty, who passed away aged 84 earlier in the week. The Scot was the only Millwall manager ever to guide the club into the top flight when they won promotion to what was then the First Division in 1988.
The Lions started the better and had the ball in the Coventry net direct from Bryan's wind-assisted 12th-minute corner, but Macaulay Langstaff was adjudged to have fouled Collins.
It took almost half an hour for either side to register a shot on goal as Coventry's Tatsuhiro Sakamoto saw an effort from the edge of the box fly over after an assist from Milan van Ewijk.
The recalled Langstaff blasted Millwall's first effort of note over eight minutes from the break after linking up with Femi Azeez, before Coventry went close to scoring as Rudoni's header from Van Ewijk's cross was tipped over by Jensen.
Jensen again kept the Lions in it when Mason-Clark got on the end of a corner from close range, but he could do nothing as the former Peterborough forward put Lampard's side in front from his next opportunity.
Van Ewijk did well on the right to find Rudoni and his cross was met by Mason-Clark at the back post with a side-footed effort that went in off the underside of the bar.
Millwall tried to fashion an equaliser, but it was Coventry who almost got a second when Thomas rose highest to meet Rudoni's out-swinging corner, but his effort hit the upright.
Millwall manager Neil Harris told BBC Radio London:
"I thought first half we were the better team, but lacked a cutting edge and a couple of chances we did have we put over the bar or wide. Second half, I thought Coventry were better than us until right at the end.
"I thought the last five minutes summed us up as a group really - we got into really good areas, just lacked the quality to hurt teams at this level.
"Today we struggled, and at the end of the game a final moment - the ball comes into the box and I've got my centre forward and wide player standing outside the penalty area."
Coventry City head coach Frank Lampard told BBC CWR:
"The first half was a bit slow from us, it's not easy to come here and the conditions were obviously very difficult.
"But there were things we could have done which we didn't do which made it difficult in the first half, it was a bit passive from us.
"We got some messages across at half-time and I'm really, really proud of them - we played quicker, created chances and probably should have been two up before that last five to 10 minutes when we had to suffer a bit.
"Really pleased with the character, really pleased with the personality of the team and it's a nice win. It's a small step forward because there's a lot to do, but we're very happy."
