Watson double seals Wasps' win
Watson double seals Wasps' winSHARE
The 26-year-old opened his account following a superb offload from Willie Le Roux and went over again before the half-hour mark to assert the visitors' dominance at The Rec.
Dan Robson was also able to snipe over for Dai Young's side as the Midlands outfit were showing the type of form which saw them finish top of the league last season.
But Bath clawed their way back into the contest following a yellow card to Watson as they dotted down twice in 10 minutes.
First Rhys Priestland and then Jack Wilson showed great composure to cross the whitewash to trim the deficit back to just five points heading into the interval.
If Wasps were dwelling on that final 10 minutes of the first half it certainly didn't show as Juan De Jongh was picked out beautifully by Robson as he burst over the try line.
Paul Grant gave Bath a shout once more but that was snuffed out minutes later as Gabiriele Lovobalavu powered over in the corner for Wasps' fifth try.
Bath still weren't done and with 15 minutes to go grabbed a lifeline courtesy of Zach Mercer who cannoned his way beneath the posts to bring Todd Blackadder's team back to within a score.
Despite a late barrage from the hosts it was Wasps who hung on to surge into second place in the league standings.
Tries: Priestland, Wilson, Grant, Mercer
Cons: Priestland 3
Tries: Watson 2, Robson, De Jongh, Lovobalavu
Cons: Cipriani 3
Yellow cards: Marcus Watson (Wasps, 28), Willie le Roux (Wasps, 63)
Bath: 15 Anthony Watson, 14 Jack Wilson, 13 Jonathan Joseph, 12 James Wilson, 11 Aled Brew, 10 Rhys Priestland, 9 Kahn Fotuali'i, 8 Zach Mercer, 7 Paul Grant, 6 Matt Garvey (captain), 5 Luke Charteris, 4 Charlie Ewels, 3 Henry Thomas, 2 Tom Dunn, 1 Beno Obano.
Replacements: 16 Michael van Vuuren, 17 Lucas Noguera, 18 Max Lahiff, 19 Elliott Stooke, 20 James Phillips, 21 Chris Cook, 22 Freddie Burns, 23 Darren Atkins.
Wasps: 15 Willie Le Roux, 14 Christian Wade, 13 Juan De Jongh, 12 Kyle Eastmond, 11 Marcus Watson, 10 Danny Cipriani, 9 Dan Robson, 8 Nizaam Carr, 7 Thomas Young, 6 James Haskell, 5 Kearnan Myall, 4 Joe Launchbury (captain), 3 Jake Cooper-Woolley, 2 Tom Cruse, 1 Simon McIntyre.
Replacements: 16 Ashley Johnson, 17 Ben Harris, 18 Marty Moore, 19 James Gaskell, 20 Guy Thompson, 21 Joe Simpson, 22 Rob Miller, 23 Gaby Lovobalavu.
Referee: Luke Pearce
Assistant referees: Hamish Smales & Adam Leal
TMO: David Rose